Gov. Gavin Newsom calls an end to the nearly 3-year-old COVID-19 state of emergency

For more coronavirus information & FAQs, visit uclahealth.org/coronavirus.

FEBRUARY, 2023

California ends COVID-19 state of emergency

Feb. 28: California Gov. Gavin Newsom declares an end to the COVID-19 state of emergency he established on March 4, 2020. The change could eventually affect cost and access to treatment and preventive services, which will be covered through November.

 

JANUARY, 2023

Jan. 27: Advisers to the U.S. Food and Drug Administration unanimously recommend that the new bivalent booster, tailored to both the original and omicron strains of COVID-19, replace the original COVID-19 vaccine first introduced in December, 2020. Unvaccinated individuals would still be offered the two-shot regimen based on the original COVID-19 strain.

DECEMBER

Dec. 28: Passengers traveling from China will need to show a negative COVID-19 test no more than two days before flying in order to enter the U.S. The new rule, which goes into effect Jan. 5, comes as China is seeing a spike on cases. Tests can be either a PCR test or an antigen self-test administered through a telehealth service, and proof must be presented to the airline before boarding. The rule will apply to passengers flying to the U.S. directly from China, or through gateway countries.

NOVEMBER

Nov. 4: The new bivalent boosters designed to boost antibodies against the currently circulating omicron strains of COVID-19 are proving effective, according to a new study by Pfizer. The drug company says that adults 55 and older who received the new booster produced antibody levels four times higher than those given an extra dose of the original vaccine.

OCTOBER

Oct. 12: The FDA authorizes updated COVID-19 booster doses for children as young as 5. The boosters, targeted toward the most recent COVID-19 variant, will be available to children age 5 to 11 for the Pfizer booster and for kids as young as 6 for the Moderna shot.

SEPTEMBER

Sept. 22: Los Angeles County public health officials announce the local health order requiring masks be worn aboard public transit and inside transportation hubs such as airports will end Friday, Sept. 23. Mask use in these settings remains “strongly recommended,” says L.A. County Public Health Director Barbara Ferrer.

Sept. 21: Los Angeles County public health officials announce new masking guidelines that allow correctional facilities and shelters to make masks optional when county circulation of COVID-19 is low. This guidance aligns with new state masking guidelines. Local officials also plan to follow state guidance going into place Sept. 23, that will change from "strongly recommending" indoor masking for the general public to "individual preference," unless a venue has specific requirements. This will take effect providing the county's case rate is less than 100 new cases per 100,000 residents.

Sept. 1: An advisory panel to the U.S. Centers for Disease Control and Prevention recommends the new omicron-specific COVID-19 booster shots for the vast majority of Americans. Official CDC recommendation is expected to follow.

AUGUST

Aug. 31: The FDA authorizes new COVID-19 booster shots targeting the BA.5 omicron variant. The new Pfizer booster is authorized for use in people as young as 12; Moderna’s version is for those 18 and older. The new doses may be available as soon as next week and can be given two months after people last received a booster dose or completed their initial COVID-19 vaccine regimen.

JUNE

June 28: An advisory panel to the FDA recommends the next round of COVID-19 booster shots be tailored to protect against the omicron variant. The FDA is expected to consider the suggestion, as well as what specific subvariants to potentially target, next month.

June 18: The Centers for Disease Control and Prevention recommends the Moderna and Pfizer COVID-19 vaccines for children as young as 6 months. Vaccines will be available beginning next week.

June 17: The FDA authorizes the use of Moderna and Pfizer COVID-19 vaccines for children as young as 6 months. Moderna’s emergency use authorization now covers children age 6 months to 17 years; Pfizer’s was expanded to include children age 6 months to 4 years, having already been available for children 5 and older. The CDC is expected to make its decision on the vaccines June 18. If approved, the shots could be available beginning next week.

June 15: An FDA advisory panel unanimously recommends authorizing COVID-19 vaccines by Pfizer and Moderna for children as young as 6 months. Pfizer’s vaccine is a three-dose regimen; Moderna’s is two doses. Both vaccines could receive emergency use authorization as early as this week and administration of doses to the youngest Americans could begin next week.

June 13: The FDA says three doses of Pfizer’s COVID-19 vaccine generates enough antibodies to prevent illness in children younger than 5. An advisory panel is set to meet June 15 to discuss recommending the regimen for the youngest Americans.

June 10: The Biden administration says it will no longer require air travelers coming to the U.S. to take a COVID-19 test within a day of their flight. The requirement, instituted in January 2021, is set to expire June 12. The CDC plans to review the need for pre-flight testing every 90 days.

June 7: FDA advisers announce their support of a two-dose regimen of the Novavax COVID-19 vaccine for adults. The vaccine uses small bits of lab-made coronavirus to trigger an immune response, a different approach than the mRNA vaccines manufactured by Pfizer and Moderna.

June 1: Pfizer asks the FDA to authorize its COVID-19 vaccine for children ages 6 months to four years, saying the three-shot regimen prompts a strong immune response in children younger than 5.

MAY

CDC make booster recommendation for children

May 19: A panel of scientific advisers to the CDC recommends children ages 5 to 11 receive a booster dose of Pfizer’s COVID-19 vaccine.

May 17: The U.S. surpasses 1 million deaths from COVID-19, according to Johns Hopkins University.

The FDA grants emergency use authorization for a booster dose of Pfizer's COVID-19 vaccine for children age 5 to 11. Children become eligible for the booster five months after completing the initial series of vaccines.

As COVID-19 hospitalizations rise again in Los Angeles County, Public Health Director Barbara Ferrer is urging residents to wear masks inside schools, stores and workplaces. Masks remain required on public transportation, airports and in transit hubs in the county.

May 16: The U.S. Postal Service announces it will mail eight more free COVID-19 tests to any U.S. household requesting them. This is the third round of free COVID-19 tests. Those interested can go to covid.gov/tests

May 5: The FDA modifies the emergency use authorization of Johnson & Johnson’s COVID-19 vaccine to adults 18 and older for whom other vaccines aren’t appropriate or accessible. The FDA says this new limit is warranted because of a risk of rare and potentially life-threatening blood clots associated with the Johnson & Johnson vaccine in some individuals.

APRIL

April 28: Moderna asks the FDA to authorize its COVID-19 vaccine for children younger than 6. The Pfizer vaccine is authorized for children ages 5 to 11 and trials are underway on COVID-19 vaccines for younger kids. Moderna’s vaccine has only been cleared for adults, but the drug company previously applied for authorization to give the vaccine to adolescents ages 12 to 17 and children ages 6 to 11.

April 26: Pfizer asks the FDA for emergency use authorization for a booster dose of its COVID-19 vaccine for children ages 5 through 11, citing research that shows that a third dose significantly raises antibodies against the omicron variant in this age group.

April 25: The FDA approves the antiviral drug remdesivir for children with COVID-19 as young as 28 days old and weighing at least 6.6 pounds. It was previously approved for children age 12 and older.

April 21: Los Angeles County Public Health officials announce that masks continue to be required on all public transit and at indoor transit hubs within Los Angeles County. This includes airports, bus and train terminals within the county, along with commuter trains, buses, subways, taxis and ride-share vehicles.

April 20: The CDC asks the Department of Justice to appeal the ruling by a Florida judge striking down masking requirements on public transportation. The CDC says it continues to recommend people wear masks in all indoor public transportation settings.

April 18: A Florida judge strikes down the federal mask mandate for transportation hubs, airports and on all public transport, saying the order overstepped the authority of U.S. health officials.

Los Angeles County Public Health announces modified quarantine requirements for asymptomatic people who have been in close contact with individuals infected with COVID-19. Regardless of vaccination status, people who have been in close contact with someone with COVID-19 do not need to quarantine, as long as they are asymptomatic, wear a “highly protective mask” when indoors around others and get tested within three to five days of virus exposure.

April 14: The FDA issues emergency use authorization for a new COVID-19 diagnostic test that analyzes chemical compounds in breath samples and delivers results in less than three minutes. Performed by a trained operator, the new test uses a piece of machinery about the size of a carry-on suitcase and can be conducted in hospitals, doctor’s offices and at mobile testing sites.

Pfizer says its COVID-19 booster shot for children ages 5 to 11 generated a strong immune response against the original version of the virus and the omicron variant. Results were based on a small study in which 140 children received a booster dose six months after their second vaccine shot.

April 13: The CDC announces it is extending federal transportation masking requirements by two weeks. It is now set to expire May 3. Masks are required in transportation hubs, airports and on all public transport.

MARCH

March 29: The FDA authorizes a second COVID-19 booster dose, either Pfizer or Moderna, for anyone 50 and older. People would be eligible four months after receiving their first booster. An additional booster dose also was approved for those age 12 and older with weakened immune systems.

March 24: The World Health Organization announces that the omicron subvariant, BA.2 - which is driving a surge of COVID-19 cases in Europe - is now the dominant version of omicron across the globe, accounting for about 86% of new infections internationally.

March 23: Moderna says it will ask the FDA for emergency use authorization of its low-dose COVID-19 vaccine for children younger than 6.

March 21: The FDA announces its advisory panel will meet April 6 to discuss the nation's COVID-19 booster strategy. The agency says it will not consider pending applications from Moderna and Pfizer for emergency use authorization of second booster shots before then.

March 17: Moderna requests FDA authorization for a second dose of its COVID-19 booster shot to be made available for adults 18 and older.

Los Angeles Unified School District announces it will no longer require indoor masking for students or staff, effective March 22.

March 15: Pfizer announces it is seeking emergency use authorization for a second booster dose of its COVID-19 vaccine for adults 65 and older. A recent study out of Israel found that people who received a second booster shot were less likely to get infected or develop severe illness from the virus.

March 10: The CDC and the Transportation Security Administration extend mask requirements on public transportation and in transportation hubs through April 18 while revised policies are developed.

March 7: The global death toll from COVID-19 surpasses 6 million.

March 3: Los Angeles County has moved into what the CDC considers a low level of community COVID-19 transmission, so county health officials say masks will no longer be required indoors in bars, restaurants, stores, offices and other businesses. The cities of Los Angeles and West Hollywood still have mask orders in place.

The NFL. and its players' union announce they are suspending all COVID-19 protocols, effective immediately, and returning to pre-pandemic operations. Masks and social distancing will no longer be required, except as dictated by local ordinances.

March 2: Los Angeles County Public Health officials announce new masking guidelines to go into effect March 4. Masks will be "strongly recommended" but not required in indoor public settings. State and federal regulations still require masks on public transportation, in health care settings, at correctional facilities, in homeless shelters and in long-term care facilities.

The White House unveils its new COVID-19 strategy, a four-pronged plan focused on testing for and treating the virus, preparing for new variants - including funding research to develop a universal coronavirus vaccine that would protect against all of them - avoiding shutdowns and increasing international outreach to fight the virus.

FEBRUARY

Feb. 28: California health officials say masks will no longer be mandatory at schools and childcare facilities statewide after March 11. Los Angeles Unified School District, however, is likely to require masks through the end of the school year, per an agreement with the teachers' union. Los Angeles County public health officials say they will align with state guidelines but continue to "strongly recommend" mask usage in schools.

The U.S. surpasses 950,000 deaths from COVID-19.

Feb. 25: The U.S. Centers for Disease Control and Prevention issues new masking guidelines according to a three-tiered system based on community transmission levels. In counties with high transmission levels, including Los Angeles County, masks are still recommended in indoor public places. About 37% of U.S. counties are considered high-transmission communities.

Feb. 23: Los Angeles County public health officials say masks will no longer be required indoors at bars, gyms, offices and other businesses for people who are fully vaccinated or who show proof of a negative COVID-19 test taken within the previous 24 to 48 hours.

Feb. 17: California public health officials say the state is moving into a new phase of COVID-19 response as the omicron surge wanes. The state plan is represented by the acronym SMARTER, which stands for shots, masks, awareness, readiness, testing, education and Rx (or therapeutic treatments). The state plan acknowledges that COVID-19 is not likely to disappear, but that preparation - and possibly even reinstatement of mask requirements - will help prevent hospitals from being overwhelmed again should a new surge arise.

Feb. 15: Los Angeles County public health officials announce that mask rules will ease beginning Wednesday, with face coverings no longer required outdoors at K-12 schools or at mega-events such as those at Dodger Stadium, Hollywood Bowl or SoFi Stadium.

The U.S. surpasses 925,000 deaths from COVID-19.

Feb. 11: The U.S. Food and Drug Administration says it will delay its decision on authorizing Pfizer's COVID-19 vaccine for children younger than 5 until data is available about the efficacy of a three-dose regimen. Previous studies found that two doses produced an inadequate immune response in children ages 2 to 4.

Feb. 7: California public health officials announce plans to lift statewide mask mandates for indoor public places next week. Mask requirements still apply in counties with local mask orders, including Los Angeles County and most of the San Francisco Bay Area.

Feb. 4: The U.S. surpasses 900,000 deaths from COVID-19.

Feb. 1: Pfizer asks the FDA for emergency use authorization of its two-dose COVID-19 vaccine regimen for children as young as 6 months, despite data showing an inadequate immune response in children age 2 to 4. Studies into the effects of a third dose are underway. Hospitalizations of younger children have surged in recent weeks to the highest levels since the beginning of the pandemic.

JANUARY, 2022

Moderna's COVID-19 vaccine gets full FDA approval

Jan. 31: The U.S. Food and Drug Administration gives full approval to Moderna’s COVID-19 vaccine, Spikevax. It is now approved for use in people age 18 and older. The FDA gave full approval to Pfizer’s COVID-19 vaccine, Comirnaty, in August.

Jan. 26: Moderna announces that it has begun testing a COVID-19 booster shot designed to target the omicron variant. The company also announced study results suggesting that its authorized booster shot provides protection against omicron that likely fades over the course of six months.

Jan. 25: The U.S. Department of Labor's Occupational Safety and Health Administration says it is withdrawing COVID-19 vaccination and testing mandates for businesses with 100 or more employees and says it will seek a new COVID-19 health care standard for companies. The Supreme Court blocked the Biden administration's vaccine and testing mandate earlier in January.

Pfizer announces it is enrolling healthy adult volunteers in a clinical trial for a reformulated COVID-19 vaccine tailored to the omicron variant, to see how it compares to the original COVID-19 vaccine. Studies show the original vaccines still offer protection against severe illness and death from omicron.

Jan. 24: The FDA says existing COVID-19 monoclonal antibody treatments are unlikely to be effective against infections caused by the omicron variant and revises its authorization of their use in these cases.

Jan. 21: The U.S. Centers for Disease Control and Prevention announces study results showing that booster doses of the Pfizer and Moderna COVID-19 vaccines not only help prevent infection from the highly contagious omicron variant, but are 90% effective in keeping those who are infected out of the hospital.

A federal judge blocks the Biden administration mandate that federal employees be vaccinated against COVID-19. The administration says more than 95% of federal workers are already in compliance. The Justice Department plans to appeal the ruling.

Jan. 19: The Biden administration announces it will make 400 million non-surgical N95 masks available free to Americans at community health centers and retail pharmacies across the country. The masks, which filter out 95% of all airborne particles, are expected to be available by the end of the month.

Jan. 14: Americans with health insurance will have costs covered for four COVID-19 tests per month beginning Saturday. They can buy the home test kits online or at retail pharmacies (though they are difficult to find right now in many parts of the country) and submit receipts for reimbursement. Some insurance companies may also create a network of retailers where test kits can be acquired for no up-front cost. Americans can also order free rapid test kits online at COVIDtests.gov beginning Jan. 19, which will ship within 12 days of being ordered.

Jan. 13: The U.S. Supreme Court blocks a Biden administration effort to mandate COVID-19 vaccinations and testing for employees of large companies across the country, but upholds a vaccine mandate for health care workers at facilities that receive federal funding.

President Joe Biden says the U.S. plans to make high-quality face masks available free to Americans, with details to be announced next week. He also says 500 million COVID-19 home test kits – on top of a previous 500 million – will be purchased for distribution. And as the latest surge overburdens hospitals, Biden also announced that military medical staff will be deployed to Michigan, New Jersey, New York, Ohio, New Mexico and Rhode Island to help with triage.

Jan. 11: World Health Organization says at the rate the omicron variant is spreading, half of Europe will be infected with it within eight weeks.

Jan. 10: The Biden administration announces that private health insurance companies must cover the cost of eight at-home COVID-19 tests per member per month beginning Jan. 15. People can show their insurance card at certain pharmacies to receive free test kits or file claims for reimbursement for test kits, which cost around $25 for a two-pack. This effort is in addition to 500 million free test kits the administration plans to provide to Americans who request them beginning later in January.

Jan. 5: The CDC recommends adolescents ages 12 to 17 receive booster doses of Pfizer's COVID-19 vaccine five months after completing the initial two-shot regimen.

California health officials extend the indoor mask mandate amid a continuing surge in COVID-19 cases. The mandate, instituted in December, was set to expire Jan. 15. It will now continue through at least Feb. 15.

Jan. 3: FDA officials authorize the Pfizer COVID-19 booster shot for children ages 12 to 15. The CDC is expected to weigh in later this week. The FDA also says people 16 and older can receive a booster five months - rather than six months - after completing the initial two-shot series of the Pfizer vaccine.

DECEMBER

Dec. 30: The CDC advises against any cruise travel, regardless of vaccination status, as COVID-19 cases aboard ship skyrocket.

Dec. 28: The U.S. sets a new record for daily number of COVID-19 cases, topping 267,000.

Dec. 27: The CDC revises its recommendation for people who have tested positive for COVID-19, shortening the isolation period from 10 days to five days provided they have no symptoms and wear a face mask when around other people for another five days minimum. The CDC also recommends people exposed to the virus, but not infected, isolate for five days if they are fully vaccinated. Exposed people who received a booster shot don’t need to quarantine if they wear a mask in all public settings for at least 10 days.

Dec. 23: The FDA authorizes the use of a second COVID-19 antiviral pill, molnupiravir, from drug maker Merck. Like Pfizer's Paxlovid, the pill is for the treatment of people with mild-to-moderate cases, before they become sick enough to be hospitalized.

Dec. 22: The FDA issues an emergency use authorization for Pfizer's Paxlovid, the first oral antiviral tablet for the treatment of mild-to-moderate cases of COVID-19. In patient trials, the medication showed 90% efficacy in preventing hospitalization and death.

Dec. 21: To address the rapidly spreading omicron variant of COVID-19, President Biden announces plans for 1,000 military medical professionals to offer support where needed and new vaccination and testing sites across the country. Biden also says his administration is buying 500 million rapid COVID-19 tests to distribute free to the public beginning in January.

Dec. 20: Moderna says its COVID-19 booster shot significantly increases antibodies against the omicron variant in laboratory studies. The booster dose is half the amount of the regular two-dose regimen.

Dec. 17: A federal appeals court reinstates a mandate requiring COVID-19 vaccination or testing at private companies nationwide with 100 or more employees. Last month, an appeals court temporarily blocked the Biden administration mandate.

The CDC endorses "test-to-stay" policies at schools, which allow close contacts of students who have tested positive for COVID-19 to remain in school if they test negative. School districts in Los Angeles using this approach have not seen an increase in infections.

Dec. 16: Advisers to the CDC unanimously vote to recommend Pfizer's and Moderna's COVID-19 vaccines over one made by Johnson & Johnson, citing a link between the J&J shot and a rare blood clot disorder.

Dec. 14: The U.S. surpasses 800,000 deaths from COVID-19.

Pfizer says laboratory studies show its antiviral COVID-19 pill protects against severe disease, including illness caused by the omicron variant.

Dec. 13: Faced with a rising number of COVID-19 cases, California health officials announce a new universal indoor mask mandate. Effective Dec. 15, everyone, vaccinated or not vaccinated, will be required to wear a mask indoors. The mandate will run through Jan. 15. Some areas, including Los Angeles County, already have an indoor mask mandate in place.

Dec. 9: The FDA authorizes a third dose of the Pfizer COVID-19 vaccine for 16- and 17-year-olds. The teens are eligible for the booster six months after completing the original two-dose regimen. Adults became eligible for the booster last month.

Dec. 8: Pfizer reports lab test results showing that three doses of its COVID-19 vaccine offer considerable protection against the omicron variant.

Dec. 7: A federal judge blocks the Biden administration from enforcing a COVID-19 vaccine mandate for employees of federal contractors. President Joe Biden had issued the mandate in September.

Dec. 6: The CDC adds five European countries to its list of more than 75 nations deemed "very high" COVID-19 travel risks. The new additions include France, Andorra, Portugal and Lichtenstein. Popular travel destinations including Greece, Croatia, Switzerland and the United Kingdom already were on the CDC list of countries recording more than 500 COVID-19 cases per 100,000 residents in the past 28 days.

Dec. 2: The Los Angeles Department of Public Health reports the first confirmed case of COVID-19 linked to the omicron variant. The person had traveled to South Africa and returned home to Los Angeles County on Nov. 22. Public Health officials report the fully vaccinated adult is self-isolating and symptoms have improved with medical care. Close contacts in the area have tested negative for the coronavirus and have shown no symptoms.

Speaking at the National Institutes of Health, President Biden announces new efforts to combat the omicron variant of COVID-19 that include expanded vaccine access for families, booster shots for all adults, new testing requirements for international travelers coming into the U.S. and insurance reimbursement for at-home COVID-19 tests. He also extended the mask mandate for travelers on planes, trains and buses and in transit terminals through mid-March.

Dec. 1: The CDC says the omicron variant of COVID-19 has been identified in a California patient, the first case identified in the U.S. The individual, who is fully vaccinated and reports mild symptoms, had traveled from South Africa to San Francisco.

NOVEMBER

Nov. 30: An FDA advisory panel recommends authorization of the first antiviral pill for COVID-19. The drug from Merck, known as molnupiravir, has been shown to reduce the risk of hospitalization and death in people vulnerable to severe illness. It could be authorized within days and be available in the U.S. by year's end. A similar pill from Pfizer also will be considered in the coming weeks. Scientists have yet to explore how these antiviral pills fare against the omicron variant.

Nov. 29: President Biden addresses the nation about the omicron coronavirus variant first identified in South Africa. He urged Americans to get vaccinated against COVID-19 or to get a booster shot if already fully vaccinated. The president said he would expedite processes should new vaccines or boosters be necessary to respond to the new variant, adding that more research is needed.

Nov. 27: President Biden announces that effective Nov. 30, travel into the U.S. will be restricted from South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi. The action follows an alert by the World Health Organization (WHO) of a COVID-19 "variant of concern," dubbed omicron, found in South Africa.

Nov. 24: The U.S. surpasses 775,000 deaths from COVID-19.

Nov. 19: The FDA approves booster doses of COVID-19 vaccines from Pfizer and Moderna for all adults, and scientific advisers to the CDC unanimously echo this recommendation. Once formally accepted by CDC director Dr. Rochelle Walensky, millions of Americans who completed their two-shot vaccine regimen at least six months ago will be eligible for booster doses. The FDA previously ruled that people receiving a booster can choose one from a different brand than they initially received.

Nov. 16: Pfizer asks the FDA to authorize its antiviral pill to treat unvaccinated people infected with COVID-19. The drug, which will be available under the brand name Paxlovid, is meant to be taken at home. Clinical trials show the medication reduces the risk of hospitalization or death when administered to high-risk, unvaccinated individuals shortly after symptoms appear. Drug maker Merck applied for authorization last month for its antiviral pill to treat COVID-19.

Nov. 9: Pfizer asks the FDA to authorize its COVID-19 booster for anyone age 18 or older. Currently, the third dose of the Pfizer vaccine is available to people 65 and older and certain at-risk groups.

Nov. 8: The city of Los Angeles implements some of the most stringent COVID-19 vaccination verification rules in the nation, requiring patrons of indoor restaurants, shopping centers, movie theaters, gyms, museums, hair and nail salons, performance venues and other spaces to show proof of full COVID-19 vaccination before entry.

The U.S. reopens its borders to fully vaccinated international travelers, ending more than 18 months of restrictions. Under the new rules, international travelers can enter the U.S. if they show proof of COVID-19 vaccination and a negative test taken within three days of their journey.

Nov. 6: A federal appeals court temporarily blocks the Biden administration's mandate requiring private-sector companies with 100 or more employees to require their workers be vaccinated against COVID-19 by Jan. 4.

Nov. 4: The Biden administration announces that private-sector companies with 100 or more employees have until Jan. 4 to ensure their workforces are fully vaccinated against COVID-19. The mandate, originally announced in September, affects 84 million workers across the country.

Nov. 3: The U.S. surpasses 750,000 deaths from COVID-19.

Nov. 2: The CDC approves Pfizer's COVID-19 vaccine for children ages 5 to 11, making shots available as soon as this week.

Nov. 1: The global death toll from COVID-19 surpasses 5 million.

OCTOBER

Oct. 29: The FDA issues an emergency use authorization for the Pfizer COVID-19 vaccine for children ages 5 to 11. The dose would be one-third the amount given to teens and adults administered in a two-dose regimen three weeks apart. The CDC still needs to make a ruling on the vaccine.

Oct. 26: An FDA advisory committee votes to recommend Pfizer's COVID-19 vaccine for children ages 5 to 11. The panel advises providing children in this age group one-third the dosage of that given to people 12 and older in two shots, three weeks apart. The CDC is set to consider the recommendation next week.

Oct. 22: Pfizer says its vaccine is 90.7% effective in preventing symptomatic COVID-19 in children ages 5 to 11. In a clinical trial, children received a 10-microgram dose of the virus, one-third the size of the dose given to adults. Participants experienced only mild side effects, Pfizer reports.

Oct. 21: A CDC advisory panel unanimously recommends booster doses for millions of Americans who received COVID-19 vaccines from Moderna or Johnson & Johnson. The panel says people who received the Johnson & Johnson shot should get a booster two months or later after the single-dose vaccination. Certain individuals initially immunized with the two-dose Moderna vaccine - people 65 and older, anyone over 18 who is at risk for serious illness from COVID-19 and people who may be exposed to the virus at work - may choose to get a booster six months or more after completing the two-dose regimen. The advisory panel also endorses the so-called mix-and-match approach, whereby booster doses may come from a different vaccine manufacturer than the original dose or doses. Booster doses for people who received the Pfizer vaccine already had been approved.

Oct. 20: The FDA authorizes booster shots for recipients of COVID-19 vaccines from Moderna and Johnson & Johnson. People age 65 and older, adults 18 to 64 at high risk of severe illness from COVID-19 and individuals with frequent exposure to the virus at work are eligible for the booster shots six months after completing Moderna's two-shot regimen or two months after receiving the Johnson & Johnson single-dose shot. The FDA also announces it will allow health care providers to "mix and match" booster doses, giving individuals a booster from one manufacturer even if the original dose or doses was from another manufacturer.

Oct. 18: The U.S. surpasses 725,000 deaths from COVID-19.

Oct. 15: An FDA advisory panel recommends a booster dose of the single-shot Johnson & Johnson COVID-19 vaccine for anyone age 18 or older. People would be elegible as early as two months after receiving the initial dose. The FDA will meet to consider the recommendation.

Oct. 14: An FDA advisory panel recommends a booster dose of the Moderna COVID-19 vaccine for people age 65 and older; those ages 18 to 64 who are at high risk of contracting severe COVID-19; and people age 18 to 64 whose jobs put them at particular risk of exposure to the virus. People would be eligible for the booster dose six months after receiving the second shot in the original two-dose series. The FDA will meet to consider the recommendation.

Oct. 11: Drug maker Merck requests emergency use authorization for the first antiviral pill to treat COVID-19 from the FDA. The drug, molnupiravir, would be the first outpatient treatment available for COVID-19.

Oct. 7: Pfizer asks the FDA to authorize emergency use of its COVID-19 vaccine for children ages 5 to 11. A ruling is expected by Thanksgiving.

Oct. 6: The Los Angeles City Council approves an ordinance requiring proof of vaccination against COVID-19 to enter indoor restaurants, movie theaters, shopping centers, gyms, museums, hair and nail salons and other indoor venues beginning Nov. 4.

Oct. 5: Johnson & Johnson says it has asked the FDA to authorize booster doses of its COVID-19 vaccine. AstraZeneca says it also has asked the FDA for authorization of its long-acting antibody treatment to prevent COVID-19 in people at high risk for the disease - the first such preventive treatment of its kind in the U.S.

Oct. 1: The U.S. surpasses 700,000 deaths from COVID-19.

California Gov. Gavin Newsom issues statewide mandate requiring COVID-19 vaccination for all eligible students of public and private schools, the first such mandate in the nation. It could take effect for students age 12 and older as early as January.

Drug maker Merck announces it will seek authorization for the first antiviral pill to fight COVID-19 after clinical trials show the drug, molnupiravir, cuts the risk of hospitalization or death in half when given to high-risk patients early in their infection.

SEPTEMBER

Sept. 23: The CDC accepts recommendations from its vaccine advisory panel to offer booster shots of the Pfizer COVID-19 vaccine to people age 65 and older, residents of long-term-care facilities and those age 50 to 64 who have underying health conditions. The CDC also recommends booster vaccines for Americans whose jobs put them at high risk of exposure to COVID-19. That includes health care workers, as well as those employed in prisons and homeless shelters.

A vaccine advisory panel to the CDC vote in favor making booster doses of the Pfizer COVID-19 vaccine available to people age 65 and older, residents of long-term-care facilities and some Americans with underlying conditions. The booster shots would be available six months after a person is fully vaccinated with the two-dose Pfizer vaccine. The panel widely favored booster doses for people ages 50 to 64 who have underlying medical conditions, and more narrowly supported third doses for people ages 18 to 49 with underlying conditions.

Sept. 22: The FDA authorizes booster shots for Americans 65 and older who received Pfizer's COVID-19 vaccine at least six months prior. Individuals at high risk of serious illness from COVID-19 or who work in industries with a high chance of virus exposure also are eligible for booster shots. The next step is for a recommendation regarding boosters from the CDC, which could come within days.

Sept. 21: Johnson & Johnson announced study results showing a second dose of its one-shot COVID-19 vaccine boosts efficacy from 74% to 94%. The study also finds protection conferred by a single dose holds steady at least five months after vaccination.

Sept. 20: The U.S. surpasses 675,000 COVID-19 deaths

Effective today, the state requires all attendees at indoor mega events – those with 1,000 or more attendees – to show proof of full vaccination or a negative test result before being allowed to enter. Mega-events would include conventions, conferences, concerts, sporting events, live entertainment and festivals.

Pfizer announces its COVID-19 vaccine for children ages 5 to 11 - one-third the amount of the current dose available for adults and older children - has proven effective in building immunity against the virus. The company says it will apply for emergency use authorization from the FDA by the end of the month.

The White House says it will loosen restrictions against international travel into the U.S. effective in November. At that time, foreign nationals traveling into the country will be required to show proof of COVID-19 vaccination before boarding a flight, as well as proof of a negative COVID-19 test taken within three days of travel. Fully vaccinated U.S. citizens returning to the country must be tested within three days of their flight and show proof of a negative result. Unvaccinated U.S. citizens will be required to test within a day before departure and upon their return to the country. Fully vaccinated passengers will not be required to quarantine upon arrival in the U.S.

Sept. 17: An advisory panel to the FDA recommends against approving booster shots of the Pfizer vaccine for the general public, saying more data is needed, but advises third doses for adults 65 and older and people at high risk of serious illness from COVID-19.

The CDC releases study data showing the Pfizer vaccine's effectiveness against hospitalization from COVID-19 drops from 91% to 77% after about four months. No such drop was found with Moderna's vaccine, according to the study.

Sept. 15: Los Angeles County officials announce they will soon require proof of COVID-19 vaccination for patrons and employees at indoor bars, wineries, breweries, nightclubs and lounges. They also will require that guests and employees have at least one dose of the vaccine by Oct. 7 and be fully vaccinated (with one- or two-dose vaccines) by Nov. 4. The new health order also will require that participants and workers at outdoor “mega events,” those with more than 10,000 attendees, show either proof of vaccination or of a negative COVID-19 test taken within 72 hours.

Sept. 10: Federal health officials release studies finding that unvaccinated individuals are 11 times more likely to die of COVID-19 than those who are fully vaccinated. Other results show the available vaccines protect against severe illness from the dominant Delta variant, though their effectiveness in preventing infection has dropped from 91% to 78% with the variant.

Sept. 9: The Los Angeles Unified School District's Board of Education mandates COVID-19 vaccines for all students 12 and older who are attending classes in person. Students will have to receive a first dose no later than Nov. 21 and a second dose no later than Dec. 19. Those who miss the deadline will not be allowed on campus.

President Biden announces sweeping COVID-19 vaccine mandates that cover two-thirds of the American workforce, including federal employees and contractors, health care workers at facilities that accept Medicare or Medicaid and private-sector workers at companies with 100 employees or more. The mandates require all businesses with 100 or more employees to ensure their workers are either vaccinated or tested weekly; that all federal employees and contractors be vaccinated without a weekly testing option; and that all health care workers at facilities receiving Medicare and Medicaid funds be fully vaccinated.

Sept. 7: The U.S. surpasses 40 million confirmed cases of COVID-19 and 650,000 deaths.

Sept. 1: The director of the Centers for Disease Control and Prevention says people who aren't fully vaccinated against COVID-19 should avoid travel over Labor Day weekend. Dr. Rochelle Walensky notes that given current disease transmission levels, even those who are fully vaccinated should consider the risks that traveling may present.

AUGUST

Aug. 25: The CDC releases data showing unvaccinated people in Los Angeles County are nearly five times more likely to become infected with COVID-19 and 29 times more likely to be hospitalized than unvaccinated people. The data comprised more than 43,000 infections recorded between May 1 and July 25, 2021.

Aug. 23: FDA grants full approval for Pfizer’s COVID-19 vaccine for people age 16 and older, making it the first COVID vaccine to move out of emergency use authorization in the U.S. The vaccine still will be available for children age 12 to 15 under emergency use status. The move is expected to increase requirements for vaccination from employers and others. Pfizer officials say they have tested the vaccine on 44,000 trial participants globally and it has be shown to be 91% effective in preventing COVID-19 infection.

Aug. 19: The U.S. surpasses 625,000 deaths from COVID-19.

Aug. 18: Los Angeles City Council votes to require city employees to be fully vaccinated against COVID-19 by early October, unless granted an exemption for medical or religious reasons.

Top U.S. health officials announce a plan to begin rolling out supplemental doses of the COVID-19 shot for those who received the Pfizer or Moderna vaccines, pending approval from the CDC and the FDA. Supplemental doses would be available beginning Sept. 20, and starting eight months after a person received the second dose of the vaccine. In a joint statement, officials said the vaccine has proven extremely effective against COVID-19 and its variants, but its ability to protect against the virus gradually diminishes. Those who received the one-shot Johnson & Johnson vaccine would not be included in this first round of supplemental doses because the vaccine wasn't first given in the U.S. until March.

Aug. 17: Los Angeles County Department of Public Health says effective 11:59 p.m. Aug. 19, all attendees at "mega" outdoor events must be masked, expect for brief periods while eating or drinking. Outdoor mega events are defined as those having more than 10,000 people in attendance.

Aug. 13: The superintendent of the Los Angeles Unified School District announces that all district employees must be fully vaccinated against COVID-19 by Oct. 15. The move, intended to protect against surges caused by the Delta variant, comes on top of a district-wide requirement that all students and staff submit to weekly coronavirus testing, regardless of vaccination status.

Echoing the FDA, an advisory panel to the CDC recommends booster shots of Pfizer's or Moderna's COVID-19 vaccines to immunocompromised Americans. The CDC is expected to adopt the recommendation, clearing the way for shots to be administered.

Aug. 12: FDA authorizes a third dose of the Pfizer and Moderna COVID-19 vaccines for certain people who have compromised immune systems. That group, which they say is about 3% of adults, includes solid organ transplant recipients, some cancer patients and others who are similarly immunocompromised. The Advisory Committee of the CDC is scheduled to meet Friday to discuss booster doses of the vaccines and additional doses for those who are immunocompromised.

The Los Angeles County Department of Public Health issues an order calling for all health care workers in the county to be fully vaccinated against COVID-19 by Sept. 30. Going beyond state requirements announced Aug. 5, the county order also mandates vaccines for emergency medical technicians, paramedics, dental-office employees and home health workers.

AEG Presents, one of the largest concert and live-event producers in the country, announces that proof of vaccination or a negative COVID-19 test will be required for all attendees and crew in the U.S. beginning Oct. 1. The company operates such venues as the Roxy and the Shrine Auditorium in Los Angeles and puts on massive music festivals including Coachella and Stagecoach in Indio.

Aug. 11: Gov. Newsom announces that teachers and other school staff statewide must be vaccinated against COVID-19 or submit to weekly testing. ​California becomes the first state to institute this requirement.

Per California Department of Public Health orders, as of 11 a.m. today, all visitors inside general acute care hospitals, skilled nursing facilities and intermediate care facilities must show documentation of COVID-19 vaccination or proof of a negative COVID-19 test within 72 hours of the visit.

Aug. 5: State health officials announce that all California health care workers — including employees of hospitals, skilled-nursing facilities, dialysis centers, doctor's offices and clinics — must be fully vaccinated against COVID-19 by Sept. 30.

JULY

July 29: President Biden announces that federal employees must be vaccinated against COVID-19 or be subject to regular testing, mask and distancing requirements, as well as travel restrictions. More than 4 million Americans are employed by the federal government.

July 28: California health officials revise masking guidelines and effective today advise all residents to wear masks at public indoor settings regardless of vaccination status.

July 27: The CDC says even fully vaccinated individuals should resume wearing masks in public indoor spaces in areas where the virus is surging. CDC officials also recommend universal masking for public school staff, students and visitors, regardless of vaccination status or virus transmission rates.

The California State University system joins the University of California in requiring students, faculty and staff to be vaccinated against COVID-19 before coming back to campus for the fall semester. Unvaccinated students granted medical or religious exemptions must undergo regular coronavirus testing.

July 26: California officials announce that state workers and health care employees will be required to show proof of COVID-19 vaccination or, if unvaccinated, be tested for COVID-19 infection weekly. The plan has not yet been implemented.

July 23: Los Angeles County public health officials confirm 3,058 new cases of COVID-19, bringing the total number of new cases to more than 10,000 in just four days. This was the first time since February that daily cases topped 3,000.

July 22: White House officials announce plans to spend $1.6 billion of approved American Rescue Plan funds on testing and other measures to reduce viral spread in high-risk settings such as prisons and homeless shelters. They also plan to send $100 million to rural health clinics to support vaccine education and outreach.

The Los Angeles Public Library system announces pop-up COVID-19 vaccination clinics at select locations. Vaccines are free for anyone over 18 and no appointments are necessary. Check lapl.org for details.

July 21: Los Angeles County health officials confirm 2,551 daily COVID-19 cases, a 20-fold increase over the 124 daily cases reported on June 21.

July 20: The CDC says the prevalence of the Delta variant of COVID-19 is increasing across the country. The variant accounts for 83% of all sequenced cases, up from 50% the week of July 3. Scientists sequence, or examine genetic information, of just a fraction of new infections each week to track different variants, but the marked increase in Delta-caused cases reflects the variant's growing presence in the U.S.

July 15: Los Angeles County health officials announce that masks will again be required indoors, regardless of vaccination status, beginning at 11:59 p.m. Saturday, July 17, to combat a steep uptick in COVID-19 cases in recent weeks.

July 14: Los Angeles County health officials report 1,315 new cases of COVID-19, marking the sixth straight day new cases have topped 1,000. There are 398 people currently hospitalized with COVID-19, up from 275 hospitalizations a week ago. Statewide, new cases of COVID-19 have nearly tripled in the last month, from about 900 a day to more than 2,600 daily, and hospitalizations have increased by almost 75% over the same period. New infections are almost entirely among people who are unvaccinated.

July 12: California officials announce a mask mandate for all K-12 schools. The state is leaving it up to individual school districts whether to ban students who are unmasked and refuse to wear a face covering provided by the school.

The FDA says it plans to issue a warning that the Johnson & Johnson COVID-19 vaccine can increase risk of Guillain-Barre syndrome, a rare neurological condition that causes the immune system to attack parts of the nervous system. The Centers for Disease Control and Prevention says the reaction has generally been reported about two weeks after vaccination and mostly in men, many age 50 or older. Though chances of developing the condition are low, they are three to five times higher in people who have received the Johnson & Johnson vaccine than among the general population. The warning would accompany one announced earlier about the vaccine's link to a rare but serious blood-clotting disorder in women. About 13 million Americans have received the single-dose Johnson & Johnson vaccine.

July 9: The CDC says teachers and students who are fully vaccinated against COVID-19 do not need to wear masks when they return to the classroom.

July 8: Pfizer announces it will seek emergency use authorization from the FDA for a booster dose of its COVID-19 vaccine. The FDA and CDC, however, say Americans who are fully vaccinated against the virus do not need a booster shot at this point.

July 6: The CDC says the highly contagious Delta variant is now the predominant strain of COVID-19 in the nation, making up 51.7% of new cases.

July 1: Los Angeles County Department of Public Health confirms 506 new cases of COVID-19, the highest daily total since mid-April. Officials say the pandemic is now almost entirely among unvaccinated county residents and the Delta variant of the coronavirus is of particular concern.

JUNE

June 30: Los Angeles County health officials report that COVID-19 cases and test positivity rates have doubled since the statewide reopening June 15. Overall transmission rates remain low, but health officials caution those who aren't fully vaccinated that there is increased risk because more people are mingling and the potentially troublesome Delta variant is circulating in the state.

CDC director maintains fully vaccinated Americans do not need to wear masks in most situations, despite guidance from the WHO advising masks and physical distancing continue in the face of the more contagious Delta variant of COVID-19. CDC Director Dr. Rochelle P. Walensky acknowledges local authorities may impose more stringent guidelines to protect the unvaccinated, as Los Angeles County health officials did when advising the use of masks indoors regardless of vaccination status. Dr. Walensky says the vaccines available in the U.S. protect against the variants circulating in the country.

June 29: Los Angeles County health officials advise everyone, regardless of vaccination status, to wear masks indoors as a precaution against the highly contagious Delta variant of COVID-19. However, the CDC says its guidance remains unchanged, and that fully vaccinated Americans no longer need masks indoors. Meanwhile, WHO officials urge even fully vaccinated people to continue wearing masks and physically distancing to protect against the Delta variant.

June 25: New research published in The BMJ medical journal finds the COVID-19 pandemic has shortened the average American life expectancy by nearly two years - and the numbers are even worse for Black and Latino people. For Black Americans, the average life span dropped from 74.7 years to 71.5 years between 2018 and 2020. Average life expectancies for Latino Americans fell from 81.8 years to 78 years over the same period, while life spans for white Americans dipped from 78.6 years to 77.3 years.

June 17: California’s Occupational Safety and Health Standards Board (Cal/OSHA) adopts guidelines that do away with masking and physical distancing requirements at most state workplaces for employees who are fully vaccinated against COVID-19. Signed into action immediately by Gov. Newsom, the revised guidelines also eliminate the requirement to have plastic partitions separating cashiers and customers. Masks will still be required for all employees and visitors in health care settings, long-term care facilities, K-12 schools and childcare settings, homeless and emergency shelters and jails and detention centers.

The U.S. Department of Health and Human services announces more than $3 billion in funding for research to develop antiviral pills to treat COVID-19 and other viruses that could cause future pandemics.

June 15: California drops most masking, distancing and capacity requirements as state economy fully reopens.

U.S. surpasses 600,000 COVID-19 deaths.

June 14: Disneyland announces that as of June 15, the theme park will no longer require visitors to wear masks or physically distance outdoors or indoors, provided they are fully vaccinated. Guests older than 2 who are not fully vaccinated will need to be masked indoors except when eating. Visitors will not be required to show proof of vaccination before entry to the park. Additionally, out-of-state visitors will be allowed entry starting June 15.

June 11: The University of California Office of the President announces it is finalizing a policy to require all UC faculty, staff, students and academic appointees to be vaccinated against COVID-19, subject to "narrow medical exemptions" and certain disabilities or religious beliefs. Vaccinations must be completed two weeks before fall term begins, which is Sept. 20 at UCLA.

June 10: President Biden announces the U.S. will buy 500 million Pfizer vaccine doses to donate to lower-income countries over the next year.

June 7: The CDC loosens its COVID-19-based restrictions against traveling to more than 110 countries. Among the nations remaining at the highest threat level are Brazil, India and Iraq. The CDC bases its guidance on the number of cases in a country.

June 4: The CDC reports the COVID-19 rate among adolescents rose from 0.6 cases per 100,000 in mid-March to 1.3 per 100,000 in April, after peaking at 2.1 per 100,000 in early January. Among those hospitalized, the CDC says, about one-third needed to be admitted to the ICU. Given these statistics, the CDC stresses the importance of COVID-19 vaccinations for adolescents and continued masking for those who aren't fully vaccinated or when otherwise required.

June 3: The Biden administration announces plans to share 80 million COVID-19 vaccine doses internationally by the end of June. Most will be distributed through the COVAX global vaccination program, officials said, with the balance going directly to countries in need. President Joe Biden also declared June a "national month of action" to encourage more Americans to get vaccinated by July 4.

MAY

May 27: Los Angeles County public health officials say COVID-19 is now disproportionately affecting Black individuals, who have the highest rates of positive cases, hospitalizations and deaths among racial groups. As of May 15, Black residents of L.A. County were dying from COVID-19 at twice the rate of Latino residents and three times the rate of white and Asian residents.

May 24: Los Angeles Unified School District Superintendent Austin Beutner announces that all LAUSD campuses will reopen for full-time, in-person instruction in the fall. Online instruction also will be offered.

Los Angeles County Public Health Director Dr. Barbara Ferrer says more than 50% of county residents age 16 and older are now fully vaccinated.

U.S. State Department advises Americans not to travel to Japan, as the nation experiences a spike in COVID-19 cases and has been slower than other countries to vaccinate its population. Though leisure travel to Japan has been cut off throughout the pandemic, this high-level advisory comes just a couple of months ahead of the Tokyo Olympics, scheduled for July 23-Aug. 8.

May 21: California health officials announce that businesses statewide can operate without COVID-19 capacity limits or physical-distancing requirements beginning June 15, and people who are fully vaccinated will no longer need to wear masks in most situations.

May 17: Dr. Mark Ghaly, head of California's Health & Human Services Agency, says the state will wait until June 15 to lift its mask mandate for people who are fully vaccinated against COVID-19. The pause is intended to give more time for people to get vaccinated and for everyone to adapt to the change.

May 13: The CDC announces that in most cases, people who are fully vaccinated against COVID-19 can go without a mask indoors and outdoors. Exceptions include visits to doctors, hospitals and long-term care facilities such as nursing homes; when traveling by public transportation; while in transportation hubs such as airports; or in prisons, jails and homeless shelters. Those who are fully vaccinated must also comply with existing local, state or tribal laws and follow workplace guidance, the CDC says.

May 12: A CDC advisory committee votes to recommend Pfizer's COVID-19 vaccine for use in children ages 12 to 15, clearing the way for inoculations to begin. President Joe Biden says more than 15,000 pharmacies across the country will be prepared to start vaccinating people in this age group beginning May 13.

May 10: The FDA grants emergency-use authorization to Pfizer's COVID-19 vaccine for use in children ages 12 to 15. Immunizations can begin once an advisory committee from the CDC reviews the data and makes recommendations for the vaccine's use in this age group.

May 4: Health officials say COVID-19 infection rates have dropped enough for Los Angeles County to move into the least-restrictive tier of California's reopening blueprint, which allows gyms, movie theaters, stadiums and museums to operate at higher capacity and saunas, steam rooms and bars that don't serve food to resume business beginning May 6.

APRIL

April 30: The U.S. surpasses 575,000 COVID-19 deaths.

Los Angeles County health officials announce the reopening of indoor arcades and indoor playgrounds – such as bounce centers and laser tag facilities – at 25% capacity with safety measures in place. In addition, bars, breweries and wineries no longer have restrictions on hours of operation and behavioral health support groups may go back to normal participant levels, with safety measures being followed.

Disneyland and Disney California Adventure reopen after an unprecedented 13-month closure. Park attendance initially is capped at 25% of capacity and masks are required for workers and guests.

April 27: The CDC says fully vaccinated Americans no longer need to wear face masks outdoors when walking, running or biking alone, with members of their household or while attending small, outdoor gatherings.

April 26: U.S. announces it will share as many as 60 million doses of its AstraZeneca COVID-19 vaccine around the world, once the vaccine is approved by the FDA, according the The Associated Press. About 10 million doses already have been produced and another 50 million are in production.

April 23: The CDC and the FDA end their pause on the Johnson & Johnson COVID-19 vaccine. Vaccinations could resume as soon as April 24.

April 22: State public health officials say fully vaccinated people from outside California may visit theme parks and other events previously restricted to in-state visitors only.

April 16: While emphasizing the efficacy of current COVID-19 vaccines, federal officials say they are beginning to develop a "next generation of vaccines" directed at emerging variants. Executives from Pfizer, Moderna and Johnson & Johnson say regular vaccine boosters against the virus are likely.

April 15: All California residents age 16 or older are now eligible to get a COVID-19 vaccine. In Southern California, residents in this age group in Los Angeles, San Diego, Riverside, San Bernardino, Santa Barbara and San Luis Obispo counties already were eligible.

April 13: Los Angeles County health officials say they are heeding the recommendations of the CDC and FDA and will pause use of the Johnson & Johnson vaccine countywide until the federal agencies complete a safety review of the shot. Vaccine providers in the county will contact people who had been scheduled to get the single-dose Johnson & Johnson vaccine about rescheduling or offering appointments for the two-dose Pfizer or Moderna vaccines.

CDC and FDA recommend a pause in the distribution of the Johnson & Johnson COVID-19 vaccine after six reported U.S. cases of blood clots potentially linked to the one-dose vaccine. More than 6.8 million doses have been administered in the U.S. A CDC advisory council will study the cases further to determine how to proceed long term. At the same time, Johnson & Johnson announced it would "proactively delay the rollout" of the vaccine in Europe. Though the clotting reaction to the Johnson & Johnson vaccine is extremely rare, patients who received the vaccine within the last three weeks should look for symptoms of these unusual clots, health officials say. Symptoms may include severe headache, abdominal or leg pain or shortness of breath. Those experiencing such symptoms should contact their health care provider or dial 211 to be connected to a medical expert.

April 9: Emerging from its first full-season closure in 98 years, the Hollywood Bowl announces plans to reopen May 15 with a free concert for frontline workers including health care personnel, grocery-store employees and delivery drivers.

April 6: State officials announce plans to fully reopen the California economy on June 15 if COVID-19 cases and hospitalizations remain low, adding that mask mandates will persist for the foreseeable future.

April 2: Los Angeles County public health officials announce that COVID-19 cases have declined sufficiently to move into the orange tier, which allows for additional businesses to reopen or expand operations, beginning Monday, April 5. Bars that do not serve meals may reopen for outdoor service; breweries, wineries and distilleries can open indoors at 25% capacity; restaurants can increase indoor capacity to 50% or 200 people, whichever is fewer; places of worship can expand indoor services to 50% capacity; movie theaters can increase capacity to 50% or 200 people, whichever is fewer; fitness centers can operate indoors at 25% capacity; hair salons, barbershops and personal-care services can operate at 75% capacity; museums, zoos and aquariums can open indoors at 50% capacity. Masking and social-distancing requirements will still apply at all of these locations.

California State Department of Public Health announces that indoor concerts, theater performances and other events will resume April 15. Guests will need to test COVID-19 negative on site or show proof of full vaccination to enter. Venue capacity will depend on individual counties, which are in different reopening tiers based on COVID-19 transmission rates.

CDC revises its travel guidelines, saying those who are fully vaccinated against COVID-19 can now travel domestically, providing they continue to wear face coverings, physically distance and wash their hands to protect others. A person is considered fully vaccinated two weeks after the second of the two-dose Pfizer or Moderna vaccine, or after the one dose of the single-shot Johnson & Johnson vaccine. For international travel, the CDC says those who are fully vaccinated should still get tested three to five days after travel, but do not need to get tested prior to leaving the U.S., unless it's required by the destination. International travelers don't need to self-quarantine after returning to the U.S. Like domestic travelers, international travelers should continue to practice safety measures.

April 1: Pfizer reports that its COVID-19 vaccine remains effective for at least six months after the second dose, based on results of its ongoing clinical trial.

MARCH

March 31: COVID-19 was the third-leading cause of death in 2020 in the U.S., behind only heart disease and cancer, the CDC reports based on data still being finalized. COVID-19 was reported as the cause, or a contributing cause, of death for 377,883 people. Heart disease caused 690,882 deaths and cancer, 598,932 deaths.

Pfizer reports its two-dose COVID-19 vaccine was 100% effective in a study of children ages 12-15 and plans to submit to the FDA for expanded emergency use authorization. The vaccine is currently available in the U.S. for people age 16 and older.

March 29: President Joe Biden says 90% of adults in the U.S. will be eligible for the COVID-19 vaccine by April 19, sooner than the original May 1 plan. The president also announced that the number of pharmacies in the federal vaccine distribution program will climb from 17,000 to 40,000 locations and that 33 million vaccine doses will be made available this week.

Federal health researchers report that the two-dose COVID-19 vaccine regimen from both Pfizer and Moderna prevent 90% of coronavirus infections two weeks after the second shot. A single dose of either vaccine was shown to prevent 80% of infections two weeks after vaccination. Researchers found both vaccines also offer effective protection against variant strains circulating in the U.S.

March 25: California Gov. Newsom announces that all California residents age 16 or older will be able to get a COVID-19 vaccine beginning April 15. Residents age 50 or older will be eligible for vaccination April 1.

President Joe Biden announces a new goal of distributing 200 million doses of COVID-19 vaccine during his first 100 days in office. Biden's original goal of having 100 million vaccine doses administered during his first 100 days was reached last week, on his 59th day in office.

March 19: CDC adjusts its physical-distancing guidelines for classrooms, saying students can be at least three feet apart, not six, providing they are wearing masks. Middle school and high school students can be within three feet as well, providing there is no high level of COVID-19 spread within the community. The CDC still advises six feet of distancing between adults and students, and among students in communal areas and while eating, when masks will be off.

March 17: Disneyland announces plans to reopen on April 30, to limited capacity. So far, guidelines limit admission to California residents only. The Grand California hotel, on Disneyland grounds, will open April 29.

March 12: The California Dept. of Public Health announces that 2 million doses of the COVID-19 vaccine have been administered to people in the state's most under-resourced communities, a milestone that will allow Los Angeles and 12 other counties to move into the less-restrictive red tier of closures. Among the changes to be allowed effective March 15 in L.A. County are the return to in-person schooling for grades 7 to 12; opening of movie theaters and indoor dining at restaurants at 25% capacity; opening of retail and personal care services at 50% capacity; and opening of gyms, fitness centers and yoga and dance studios at 10% capacity.

March 11: President Biden announces that he is directing all states, tribes and territories to make every adult eligible to be vaccinated against COVID-19 by May 1. "July 4 with your loved ones is the goal," he says.

March 9: Disneyland announces it's plan to re-open in late April, as COVID-19 cases continue to decline. No exact date was given.

March 8: The CDC issues new guidelines for people who are fully vaccinated against COVID-19, saying it's OK to gather indoors with other fully vaccinated people without wearing a mask or physically distancing. However, the CDC still advises fully vaccinated people to continue to wear masks and keep physically distanced when out in public, and to avoid large- or medium-size crowds. The CDC says fully vaccinated people may also gather, unmasked, with non-vaccinated people in the same household as long as the latter are at low risk for severe disease. Fully vaccinated is defined by the CDC as being two weeks past the second dose of the Pfizer or Moderna vaccines or of the single dose of the Johnson & Johnson vaccine.

March 5: California health officials announce that outdoor sports, live performances and theme parks will be allowed to reopen with limited capacity, to in-state visitors only, as soon as April 1 in counties reporting fewer than seven new daily COVID-19 cases per 100,000 residents. Capacities can increase as cases decline.

March 4: California officials say 40% of vaccine doses will be directed to the state's most vulnerable areas to inoculate residents at highest risk of COVID-19 infection and to speed reopening of the economy. About 8 million people in 400 ZIP codes - including many in Los Angeles County and the Central Valley - will be eligible for the newly allocated shots.

March 2: President Biden says there will be enough COVID-19 vaccine available for every American adult by the end of May, following the announcement of a partnership between Merck and Johnson & Johnson to speed up production.

FEBRUARY

Feb. 27: FDA grants emergency use authorization (EUA) for Johnson & Johnson's COVID-19 vaccine. It's the first single-dose coronavirus vaccine available in the U.S.

Feb. 23: Los Angeles County surpasses 20,000 COVID-19 deaths.

Feb. 22: The U.S. surpasses 500,000 COVID-19 deaths.

Feb. 16: Schools for students in grades pre-kindergarten through sixth are eligible to reopen in Los Angeles County. Twelve school districts, including Los Angeles Unified, have submitted required paperwork and have been approved to reopen, though exact reopening dates will be determined by individual school communities, according to Los Angeles County Public Health Director Dr. Barbara Ferrer.

County health officials announce that educators, emergency responders and workers in childcare, food service and agriculture will be eligible for vaccination beginning March 1.

Feb. 12: The CDC calls for K-12 schools to reopen, providing science-based guidelines for doing so safely that include universal mask-wearing, social distancing, frequent hand washing, cleaning and ventilating school facilities and contact tracing. How quickly schools can open depends on a community's daily new COVID-19 case count and the percentage of positive tests over a certain time period.

California health officials announce that people between the ages of 16 and 64 who are disabled or at high risk for mortality or morbidity from COVID-19 will be eligible to be vaccinated beginning March 15. Conditions for eligibility include cancer, chronic kidney disease above stage four, immunocompromised organ-transplant recipients, coronary artery disease, type II diabetes, Down syndrome and severe obesity.

Feb. 11: The coronavirus variant first identified in South Africa is identified in two California patients.

CVS Health announces that its pharmacies in California will begin distributing COVID-19 vaccines on Feb. 12.

Feb. 4: Johnson & Johnson submits an application to the FDA seeking emergency use authorization (EUA) for its single-dose COVID-19 vaccine.

COVID-19 deaths in the U.S. top 450,000.

Feb. 3: The federal COVID-19 task force announces it will open two new community vaccination sites in California, including one on the campus of Cal State Los Angeles. The sites in Los Angeles and Oakland will be staffed by workers from the Federal Emergency Management Agency and the Department of Health and Human Services.

Feb. 1: CDC begins requiring masks be worn when traveling by bus, subway, taxi, ride-share, plane, ship or ferry. The mask requirement, which goes into effect at 11:59 p.m., also applies to anyone inside an airport, train station, bus station and any other transportation hub.

JANUARY, 2021

Jan. 29: European Union drug regulators authorize use of the COVID-19 vaccine developed by AstraZeneca.

Jan. 28: A COVID-19 variant originally identified in South Africa has been diagnosed in the U.S. for the first time, in two cases in South Carolina, health officials announce.

Jan. 26: The number of confirmed COVID-19 cases globally tops 100 million.

Jan. 25: Gov. Newsom cancels the state's stay-at-home order, which he instituted Dec. 3. Los Angeles County officials respond by announcing numerous changes, among them the opening of personal care services, such as hair salons, at 25% capacity beginning today. Restaurants will be allowed to offer outdoor dining service starting Jan. 29.

Jan. 24: U.S. surpasses 25 million confirmed COVID-19 cases.

Jan. 23: Los Angeles County surpasses 15,000 COVID-19 deaths since the start of the pandemic.

Jan. 21: President Biden announces a national strategy for COVID-19 response that includes support from the Federal Emergency Management Agency (FEMA) which will establish vaccination centers, train vaccinators and serve as liaisons for each state; directives to the departments of Education and Health and Human Services to provide guidance and resources to reopen schools and childcare centers; the establishment of a COVID-19 testing board; mandatory testing and quarantine for travelers coming to the U.S. from other countries; and a request that all Americans wear masks for the next 100 days, which Biden calls "a patriotic act" that can save 50,000 lives.

Jan. 20: On his first day in office, President Biden signs executive orders requiring masks and physical distancing at all federal buildings and lands, including national parks and forests; establishing a federal COVID-19 coordinator; and restoring the National Security Council's global health security team.

Jan. 19: U.S. death toll from COVID-19 tops 400,000.

California tops 3 million confirmed COVID-19 cases.

Los Angeles County Public Health officials announce the opening of five new large-scale vaccination sites, including The Forum in Inglewood, Fairplex in Pomona and Six Flags Magic Mountain in Valencia.

Jan. 16: Los Angeles County surpasses 1 million cases of COVID-19.

Jan. 15: The worldwide COVID-19 death toll tops 2 million.

Jan. 14: Calling the U.S. vaccine rollout "a dismal failure," president-elect Joe Biden pledges to commit $400 billion to fight the pandemic, including the administration of 100 million vaccine doses during his first 100 days in office and the opening of most kindergarten-through-eighth-grade schools during that same period.

Jan. 13: The U.S. reaches 4,400 COVID-19 deaths in a single day.

Jan. 12: U.S. Centers for Disease Control and Prevention (CDC) announces that, beginning Jan. 26, all international airline passengers bound for the United States must be tested for coronavirus within three days of their departure and show proof of negative results before boarding their flight.

Federal government tells states to begin vaccinating all Americans age 65 and older to help stem the surge of COVID-19 cases, adding that vaccine supply held in reserve to provide required second doses will be released immediately.

Jan. 11: Los Angeles County Public Health Director Barbara Ferrer advises essential workers – those who leave their home daily for work – as well as people who regularly run errands for family, to wear masks inside their own homes to avoid spreading COVID-19 to family members.

Jan. 7: U.S. surpasses 4,000 daily COVID-19 deaths.

Jan. 6: U.S. reports a daily record 3,964 COVID-19 deaths.

Jan. 4: Britain announces a nationwide lockdown amid a spike in COVID-19 cases linked to the mutated strain.

Jan. 3: Total of U.S. deaths from COVID-19 surpasses 350,000.

Jan. 2: Los Angeles County tops 800,000 confirmed cases of COVID-19. It took 10 months to reach 400,000, on Nov. 30, but just more than a month to double that total.

Jan. 1: U.S. surpasses 20 million confirmed cases of COVID-19 since the beginning of the pandemic.

DECEMBER

Dec. 30: Los Angeles County surpasses 10,000 COVID-19 deaths since the start of the pandemic.

Gov. Newsom says the mutated coronavirus strain responsible for the majority of new COVID-19 infections in the U.K. has been identified in Southern California.

Britain becomes the first country to grant emergency use authorization to the COVID-19 vaccine developed by drug maker AstraZeneca and the University of Oxford.

Dec. 29: California health officials announce the stay-at-home order for Southern California and the San Joaquin Valley will remain in effect as ICU beds remain exceedingly scarce. The order will be in effect for at least three weeks.

A mutated strain of the coronavirus responsible for the majority of new COVID-19 infections in the U.K. is identified in the U.S. for the first time, in a Denver patient.

Dec. 23: Pfizer and BioNTech reach an agreement with the U.S. government to supply the country with 100 million more doses of their COVID-19 vaccine by the end of July.

Dec. 22: Los Angeles County surpasses 9,000 confirmed COVID-19 deaths.

Dec. 21: France and other members of the European Union restrict travelers from Britain over fears that a more-transmissible variant of coronavirus is spreading through London and surrounding areas.

Dec. 18: The U.S. Food and Drug Administration grants emergency use authorization to the COVID-19 vaccine from Moderna, with doses expected to ship immediately.

U.S. tops 17.2 million confirmed COVID-19 cases.

Dec. 17: An FDA advisory panel, made up of scientists and infectious disease specialists, recommends the approval of the Moderna COVID-19 vaccine.

Dec. 16: UCLA Health begins administering Pfizer vaccines to health care workers.

Dec. 15: Pfizer vaccines begin arriving at UCLA Health.

In a review posted online, the U.S. Food and Drug Administration praises the efficacy and safety of the Moderna COVID-19 vaccine. A panel of experts is expected to advise the FDA, Thursday, on whether to grant emergency use authorization to the vaccine.

Dec. 14: First COVID-19 vaccine is administered, at Long Island Jewish Medical Center in Queens, N.Y. The US death toll from COVID-19 surpasses 300,000.

Dec. 13: Western States Scientific Safety Review Workgroup confirms safety and efficacy of the Pfizer COVID-19 vaccine, allowing distribution to go forward in California, Nevada, Oregon and Washington.

Dec. 12: Trucks stocked with the Pfizer vaccine begin rolling out for delivery to nearly 150 sites across the country.

Dec. 11: The FDA approves emergency use authorization for Pfizer's COVID-19 vaccine, allowing nationwide distribution to begin.

Dec. 10: A panel of scientists and infectious disease specialists that advises the FDA formally recommends that the agency grant emergency use authorization to the Pfizer vaccine.

Dec. 8: The U.S. tops 15 million confirmed COVID-19 cases. The U.K. delivers its first COVID-19 vaccine, manufactured by Pfizer/BioNTech. It's the first vaccine given outside of a clinical trial.

Dec. 7: Los Angeles Unified School District Superintendent Austin Beutner announces that schools will close on Dec. 10 for the remainder of 2020. This move will affect the 1% of L.A. Unified students, about 4,000, who have been receiving services on campus, including kindergarteners and students with special needs. Classes for all students will continue online.

Gov. Newsom announces a statewide, voluntary cellphone-based program launching Dec. 10 that notifies residents if a recent close contact has tested positive for COVID-19.

Dec. 6: ICU bed capacity of less than 15% in Southern California and the San Joaquin Valley trigger the state's three-week stay-at-home order for both regions, effective at 11:59 p.m.

Dec. 3: Gov. Newsom announces a modified 21-day statewide shutdown targeting counties facing shortages of hospital beds and other critical care services. President-elect Biden tells CNN he plans to ask Americans to wear masks for his first 100 days in office.

Dec. 2: The U.S. reports its largest single-day COVID-19 death toll since the start of the pandemic: more than 3,000. Britain issues emergency authorization for the Pfizer vaccine.

Dec. 1: The Advisory Committee for Immunization Practices advises the CDC that health care workers and residents of long-term care facilities should be first in line for COVID-19 vaccines in the U.S.

NOVEMBER

Nov. 30: Moderna seeks emergency use authorization from the FDA for its COVID-19 vaccine. Confirmed COVID-19 cases in the U.S.: More than 13.4 million.

Nov. 23: AstraZeneca announces that early data show its COVID-19 vaccine to be at least 70% effective. Confirmed COVID-19 cases in the U.S: 12.4 million.

Nov. 20: Pfizer seeks emergency use authorization from the FDA for its COVID-19 vaccine.

Nov. 18: The U.S. surpasses 250,000 COVID-19 deaths.

Nov. 17: The FDA authorizes the first at-home, prescription coronavirus test.

Nov. 16: Moderna reports preliminary data show COVID-19 vaccine is more than 94% effective.

Gov. Newsom orders most non-essential businesses statewide to close and health officials say Californians must wear masks outside their homes.

Nov. 15: There are more than 11 million confirmed COVID-19 cases in the U.S.

Nov. 13: The U.S. adds more than 184,000 confirmed COVID-19 cases, the fourth consecutive day the country has set a record for daily infection diagnoses.

Nov. 12: California surpasses 1 million diagnosed COVID-19 cases.

Nov. 9: Pfizer announces preliminary results of its vaccine tests that indicate it’s 90% effective in preventing COVID-19. There are 10 million confirmed coronavirus cases in the U.S.

Nov. 8: Diagnosed COVID-19 cases worldwide top 50 million.

OCTOBER

Oct. 22: Remdesivir becomes the first drug approved by the FDA to treat COVID-19.

Oct. 1: President Donald Trump announces he has tested positive for coronavirus.

SEPTEMBER

Sept. 28: The worldwide coronavirus death toll tops 1 million.

Sept. 22: The coronavirus death toll in the U.S. tops 200,000.

AUGUST

Aug. 31: The U.S. reports more than 6 million diagnosed COVID-19 cases. California reports 700,000.

Aug. 10: There are more than 20 million coronavirus cases worldwide, with more than 5 million in the U.S.

Aug. 7: California reports more than 10,000 COVID-19 deaths.

JULY

July 27: Pfizer and Moderna begin large-scale trials of potential COVID-19 vaccines with around 30,000 volunteers each.

July 13: Gov. Newsom orders all bars to close statewide, along with indoor dining and movie theaters.

July 11: The WHO acknowledges that airborne transmission of coronavirus is possible.

JUNE

June 29: Los Angeles County officials announce beaches will be closed for the July 4 holiday weekend. The county becomes the first in the nation to announce 100,000 coronavirus diagnoses.

June 18: Gov. Newsom issues a statewide mask mandate.

June 16: UCLA Health installs thermal cameras at medical-building entrances to quickly scan for fevers.

June 1: Los Angeles County allows restaurants and hair salons to reopen for some in-person services.

MAY

May 6: UCLA Health begins in-house serology testing for COVID-19.

May 1: Remdesivir receives emergency use authorization to treat hospitalized COVID-19 patients.

APRIL

April 16: UCLA Health implements universal masking.

April 3: CDC and White House Coronavirus Task Force recommend Americans use face coverings in public.

April 1: Gov. Newsom announces California schools will be closed for the remainder of the academic year.

MARCH

March 31: UCLA Health begins involvement in clinical trials for COVID-19 treatments.

March 27: Los Angeles County beaches close. Disneyland and Disney World close.

March 19: Gov. Newsom issues statewide shelter-in-place order, the first in the nation. Los Angeles Mayor Eric Garcetti announces “safer at home” order for the city and county. Most retail businesses, other than those deemed essential, are closed.

March 13: President Trump declares national emergency. Los Angeles Unified School District announces school closures beginning March 16.

March 12: Major League Soccer and National Hockey League suspend their seasons. Major League Baseball suspends Spring Training and delays opening day.

March 11: WHO declares coronavirus a pandemic. President Trump bans travelers from parts of Europe from entering the U.S. for 30 days. NBA suspends season. Public health officials announce first coronavirus death in Los Angeles County.

March 10: UCLA Health implements in-house testing for COVID-19. UCLA campus moves to online instruction.

March 4: Gov. Newsom declares a state of emergency in California. Los Angeles County declares state of emergency. UCLA Health convenes COVID-19 command center.

March 3: CDC says face-mask use in public is not recommended.

FEBRUARY

Feb. 26: First case of local transmission in the U.S. is a Northern California resident who did not travel or have contact with anyone known to have coronavirus.

Feb. 11: WHO renames novel coronavirus COVID-19.

Feb. 6: A California woman dies, later confirmed from coronavirus — the first coronavirus death in the U.S.

JANUARY

Jan. 31: U.S. Health and Human Services secretary Alex Azar declares a national public health emergency.

Jan. 30: World Health Organization declares “public health emergency of international concern” for only the sixth time in its history.

Jan. 25, 2020: CDC confirms California’s first coronavirus case: an Orange County patient who was a traveler from Wuhan, China. It’s the third case in the U.S.