COVID-19 timeline: Track the latest developments and look back at how the pandemic evolved
Timeline will be updated as new information is announced.
It's challenging to keep up with the latest developments in the COVID-19 pandemic and the vaccines to fight it. Whether it’s the Delta variant surge, the number of new cases or changes in local and state guidelines, information changes frequently.
This timeline will help you keep track of what's happening.
Get the latest COVID-19 vaccine information at uclahealth.org/vaccine.
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Sept. 17: An advisory panel to the U.S. Food and Drug Administration 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 Centers for Disease Control and Prevention 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 Joe 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 sabys 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.
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: California Gov. Gavin 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 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 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 World Health Organization 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 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 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 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.
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.
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.
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.
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.
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.
Sept. 28: The worldwide coronavirus death toll tops 1 million.
Sept. 22: The coronavirus death toll in the U.S. tops 200,000.
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 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 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 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 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 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.
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.
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 confirm 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.