COVID-19 timeline: Reflecting on how it began and how far we’ve come

UC Davis Health nurse working with a COVID-19 patient

UC Davis diagnosed and treated the nation’s first-known case of community-spread COVID‑19 in February 2020. Since then, we have remained at the forefront of the global pandemic response.

In the two years since that first case, our health experts have continued to care for our community. UC Davis Health was among the first to administer COVID-19 vaccines to the public, and we still offer COVID vaccines and boosters to anyone who wants them. We've provided the latest information on COVID testing and participated in many clinical trials and research opportunities to help save lives.

“Since that first day, every person at UC Davis Health has played a vital role as we confronted this unprecedented crisis,” said David Lubarsky, UC Davis Health’s CEO and the Vice Chancellor of Human Health Sciences for UC Davis. “They’ve shown the utmost grace under pressure, while serving our patients and collaborating with our community partners in the interest of public health — for everyone.”

Take a look back at all we've gone through and accomplished together as a community between December 2019 and April 2022.

April 2022


Learning lessons of long COVID

Two years into the COVID-19 pandemic, UC Davis experts reveal more of what they’ve learned about long COVID and the patients who experience lasting symptoms. Read more: 9 things we've learned about COVID long haulers

March 2022


man speaking to nurse in clinic office

Mar. 8UC Davis Health partners with Pfizer on two new clinical trials to test the COVID-19 booster vaccine in healthy adults. These trials look to test the effectiveness of different strength booster doses and test heart muscle protein levels after a booster shot.

January 2022


Omicron takes over as the dominant strain of COVID-19 in the U.S., causing an uptick in cases and long lines for COVID-19 tests.


Jan. 25 Paxlovid is available at UC Davis Health

UC Davis Health begins use of Pfizer’s COVID-19 treatment pill Paxlovid. For the time being, it’s only given at UC Davis Medical Center and outpatient clinics to protect at-risk patients.


Jan. 14 CDC recommends N95 masks

The CDC updates its mask recommendations to note that N95 or KN95 are the best faces masks to protect against the omicron variant and other COVID-19 mutations.


Jan. 20 – UC Davis researchers explain one of the key COVID-19 symptoms: why people lose their sense of smell.


Jan. 25 Treating COVID-19 patients with a pill

UC Davis Health is one of the first places in Northern California to treat patients with a pill to slow COVID-19.

December 2021


people talking at testing site
A child of farmworkers gets her COVID-19 test with her mother watching at Madison Migrant Center near Woodland.

Dec. 1 – UC Davis research shows vaccinated health care workers have low risk of spreading COVID-19 to others.


Dec. 20 UC requires health care workers get COVID-19 boosters

The UC Office of the President announces that all UC health care workers are required to receive a COVID-19 booster dose by Jan. 31, 2022.


Dec. 28 UC Davis Medical Center treats record number of COVID patients

The hospital sees a record high 300 patients in the Emergency Department. This is due to a combination of COVID-related illnesses, flu, traffic accidents, and patients with chronic diseases.


Dec. 29 – UC Davis outreach efforts test 17,000 people to slow COVID-19 spread in migrant communities.

November 2021


Nov. 2 Pfizer vaccine approved for children age 5-11

A few days after the FDA approved COVID-19 vaccines for children ages 5-11, the CDC also recommends pediatric vaccinations for the Pfizer vaccine.


Nov. 19 – For the third time, the CDC expands eligibility for COVID-19 booster shots to everyone age 18 and older who received a Pfizer or Modern vaccine.


Nov. 26 Omicron is the newest variant

A new variant is classified and named Omicron by the WHO after first being discovered a few days earlier in South Africa.

October 2021


UC Davis Health physicians at a community vaccine clinic
UC Davis Health and School of Medicine staff were eager to give out COVID-19 vaccinations in underserved communities.

UC Davis School of Medicine leads effort to vaccinate underserved communities

Several physicians from UC Davis School of Medicine volunteer their time to connect with community partners across the Sacramento region to set up pop-up COVID-19 vaccination clinics. They visit grocery stores, churches, schools and other popular spots in neighborhoods with low vaccination rates.

Oct. 21 Booster eligibility expanded

The CDC announces an expanded eligibility for COVID-19 booster and third doses to include anyone age 18 and older who received a Johnson & Johnson vaccine, as well as those who work in jobs where there is a high risk of getting COVID-19.

September 2021


Sept. 1University of California reaches deadline requiring all employees, staff and students to be vaccinated against COVID-19 or have an informed exemption completed. View the UC Davis Health study that shows how quickly COVID-19 vaccines reduced infections among health care workers.


COVID-19 booster doses approved for the first time

The FDA and CDC approve COVID-19 booster or third doses for certain at-risk populations, such as those who are immunocompromised or people age 65 and older.

July 2021


A newer and more contagious strain of COVID-19, called the Delta variant, becomes of greater concern as areas across the U.S. see a spike in cases, even among vaccinated Americans.

June 2021


June 15 California reopens

After more than a year of COVID-19 restrictions, California lifts capacity limits and social distancing requirements. Vaccinated people are also allowed to be indoors without a mask.

May 2021


teen getting covid-19 vaccine at UC Davis Health

May 10Children 12-15 can get the COVID-19 vaccine

The FDA gives emergency use authorization for the Pfizer vaccine to be used in children ages 12-15.

April 2021


Apr. 1 COVID-19 vaccine eligibility expands for more adults

Californians 50 years and older are eligible to receive the COVID-19 vaccine.


April 15 – Californians age 16 and older are eligible to receive the COVID-19 vaccine. However, Pfizer is the only approved shot for ages 16 and 17.

March 2021


Mar. 8CDC announces people who are fully vaccinated can start returning to normal life.

February 2021


Feb. 2Shielding a city from COVID-19

The Healthy Davis Together COVID-prevention project is the most ambitious of its type in the country and could be a model for other universities, the New York Times notes in a feature article. The joint City of Davis-UC Davis initiative aims to facilitate a coordinated and gradual return to regular activities and reintegration of UC Davis students, while preventing the spread of COVID-19 in the Davis community.

Patient receiving COVID-19 vaccine

Feb. 6Helping reach vulnerable communities

UC Davis Health partners with the Sacramento County Department of Public Health and Dignity Health to host the first of many planned community-based COVID-19 vaccination clinics, designed to reach vulnerable populations.


Feb. 21 – As U.S. deaths top 500,000, UC Davis Health delivers more than 50,000 COVID-19 vaccines.

January 2021


woman getting covid-19 vaccine at UC Davis Health

Jan. 12UC Davis Health launches COVID-19 patient vaccinations

UC Davis Health announces it will begin vaccinating its patients. The initial group of patients is identified as the most vulnerable: those age 75 and older with underlying conditions.


Jan. 15 – Global COVID-19 deaths reach 2 million.


Jan. 26COVID-19 vaccinations expand for patients

UC Davis Health announces it's opening vaccinations to patients age 65 and older.


Jan. 28Farmworker safety initiative

To help reduce the pandemic’s impacts on California’s 800,000 farmworkers, UC Davis launches the COVID-19 Statewide Agriculture and Farmworker Education training and safety program. The state-funded project is led by experts at the UC Davis Western Center for Agricultural Health and Safety, which includes investigators from the UC Davis School of Medicine and the UC Davis School of Veterinary Medicine.


Jan. 28Multiple COVID-19 clinical trials underway locally

The UC Davis School of Medicine announces it's actively recruiting for more than a dozen clinical trials in the search for new COVID-19 treatments.

December 2020


woman getting her covid-19 vaccine
The Novavax clinical trial enrolled participants in the U.S. and Mexico in an effort to prioritize those who are most affected by COVID-19, including underrepresented minorities.

Dec. 7Another vaccine trial underway

UC Davis Health launches clinical trials for the easier-to-store Novavax COVID-19 vaccine. The overall trial prioritizes highly impacted groups such as Latino, African American and Native American communities.


Dec. 11First COVID-19 vaccine approved

The FDA authorizes the Pfizer-BioNTech COVID-19 vaccine for emergency use after data shows 95% efficacy.


Dec. 11A new COVID-19 exposure-warning app

The state of California rolls out CA COVID Notify. The Bluetooth-driven app sends anonymous notifications when users have been in close contact with someone who tests positive for COVID-19. UC Davis and six other UC campuses pilot the project, based on Google and Apple’s exposure notification technology.


A nurse receives the first Pfizer/BioNTech at UC Davis Health
Clinical nurse Eva Teniola is the first person and employee at UC Davis Medical Center to receive a COVID-19 vaccine.

Dec. 15Pfizer COVID-19 vaccine arrives

As the U.S. death toll surpasses 300,000, UC Davis Health becomes among the nation's first health systems to receive an initial allotment of the Pfizer-BioNTech COVID-19 vaccine. It begins inoculating frontline health care workers three hours later. California targets UC Davis Health for the vaccine due to its storage capability, highest-risk health care population, and community distribution ability.


Dec. 18 – The FDA approves the Moderna vaccine for emergency use.


Dec. 22Moderna vaccine arrives

In a dose of holiday good news, UC Davis Medical Center receives its initial allotment of the Moderna vaccine. Data from clinical trials suggests the COVID-19 vaccine is 94% effective.

November 2020


Nov. 12‘Nothing else as fast and accurate’

UC Davis Health becomes the first in the region and among the first in the nation to use rapid, combined molecular tests at the point of care. The highly accurate rapid test can check for both COVID-19 and flu in minutes.

October 2020


Oct. 1 Free COVID-19 testing for Central Valley farmworkers

Four UC Davis research centers receive a $3.7 million NIH grant to test workers in the Central Valley, where the COVID-19 pandemic has reached alarming levels.

Pulmonary Clinic
Teams of experts at the new Post-COVID-19 Clinic work to help patients who battle complex, long-lasting symptoms.

Oct. 12Can an antibody cocktail prevent COVID-19 infection?

UC Davis Health participates in a clinical trial of the Regeneron monoclonal antibody combination. But this time, the aim is to prevent infection in people with close exposure to a diagnosed patient, such as a household member.


Oct. 28UC Davis Health launches region's first clinic for long haulers

UC Davis Health launches a Post-COVID-19 Clinic, becoming one of only a handful of U.S. health systems with a dedicated venue for so-called "long-haul" patients.

September 2020


Sept. 10 Telehealth for at-risk Central Valley residents

The ACTIVATE initiative, a public-private pilot to bring telehealth services to underserved rural residents like farmworkers, is launched in Merced County.


Sept. 14 Pushing to prevent a ‘twindemic’

To avoid overlapping respiratory illness and preserve hospital capacity for COVID-19 surges, UC Davis Health promotes the importance of flu vaccinations during the pandemic. Drive-through flu shot events also help boost participation.


UC Davis Health physician Roderick Fontenette (far right), also an Air Force Lt. Col., was deployed to Fresno to fight COVID-19.
Several UC Davis Health physicians, who are military members, were deployed across the country and around the world in the fight against COVID-19.

SeptemberMilitary doctors battle against COVID-19

Emergency medicine physician and Army reservist Josh Elder returns from overseas deployment supporting special-ops troops with trauma care and COVID-19 prevention. He’s one of a number of UC Davis Health military members fighting against COVID-19 both home and abroad. In addition, emergency medicine physician and Air Force Lt. Col. Rory Stuart was awarded the Bronze Star for early COVID-response work in Afghanistan.


Sept. 16Historic respiratory pandemic, meet historic wildfires

UC Davis pulmonologists help Californians understand how heavy wildfire smoke increases COVID-19 risks and which respiratory symptoms indicate COVID-19.


Sept. 28 – Global deaths from COVID-19 reach 1 million.

August 2020


Patient participating in clinical trials
More than 200 people participated in UC Davis Health’s clinical trial for the Pfizer-BioNTech vaccine, which enrolled more than 40,000 participants worldwide.

Aug. 12 Part of a major COVID-19 vaccine trial

UC Davis Health partners with Pfizer Inc. and Germany based BioNTech SE to participate in a global study of an investigational COVID-19 vaccine. The first of the university’s 200 vaccine candidate participants receive their shots a week later.

July 2020


July 20 Testing an antibody cocktail

UC Davis Health announces a federal grant to test a new antibody combination as a possible therapy for reducing viral shedding and disease progression.

Expert advice for stressed family caregivers

The Family Caregiving Institute at the Betty Irene Moore School of Nursing provides actionable advice for Americans caring for aging spouses or parents during the COVID-19 pandemic. It offers road maps for supporting older relatives during social distancing, reducing their transmission risk, recognizing infection, and providing or obtaining care.


July 23 A new ICU partnership in a hotspot county

UC Davis Health and Adventist Health Lodi Memorial partner to launch a 24/7 telehealth link between the Lodi hospital’s intensive care unit. The ICU has been caring for many COVID-19 patients in highly impacted San Joaquin County.


July 30 Clinical guidance to help improve patient care

A primer on coronavirus and diagnostic errors becomes the latest COVID-19 clinical guide released by the Agency for Healthcare Research and Quality Patient Safety Network (PSNet). It's co-edited by internal medicine professor Patrick Romano and nursing professor Debra Bakerjian. The primer aims to improve care for all patients and points out that delayed diagnosis can lead to delayed treatment or preventable COVID-19 transmission.

May 2020


May 14 Panel examines COVID-19 pandemic disparities

The UC Davis Health Office for Health Equity, Diversity and Inclusion hosts a panel to explain reasons for health disparities related to COVID-19, and what can be done. Physicians at “COVID-19: Addressing Health Disparities in the African American Community” say that social determinants of health are a major reason African Americans and Latinos in California are infected with COVID-19 at rates higher than whites.


Mid-May Helping in New York as it's overrun by COVID-19

Two emergency physicians, Alex Schmalz and Nick Sawyer, from UC Davis Health travel to Elmhurst Hospital in New York to help medical personnel overwhelmed by the large number of COVID-19 cases. UC Davis Health nurse practitioner Paula Wagner also volunteers her time for 13 days at a Brooklyn hospital.


An illustration of the swab test distributed by UC Davis Health trended nationally in the early pandemic, ranking high on search engines.
An illustration of the COVID-19 nasal swab test distributed by UC Davis Health trended nationally in the early pandemic.

May 19 Tracking a troubling syndrome in children

UC Davis Children’s Hospital becomes part of an international group researching multisystem inflammatory syndrome in children (MIS-C). Researchers deem this a new form of COVID-19 likened to toxic shock syndrome and Kawasaki disease.


May 21 UC Davis Health performs 10,000th COVID-19 test

Clinical pathologists perform their 10,000th COVID-19 molecular test. UC Davis is able to test all hospitalized patients at UC Davis Medical Center to help ensure safety at the facility. The health system also processes tests gathered at community sites — which helps identify that working-age Latinos are getting infected and dying in disproportionately high numbers.


May 28 – U.S. COVID-19 deaths exceed 100,000.

April 2020


coronavirus testing
In its initial days, UC Davis Health Clinical Laboratory specialists developed the capacity to run 400 COVID-19 tests a day, knowing the device eventually had the capacity to perform more than 1,000 tests per day.

Apr. 6Boosting California’s COVID-19 testing capacity

After steadily increasing its own testing, UC Davis Health is named to California Gov. Gavin Newsom’s COVID-19 Testing Task Force, a public-private collaboration to increase statewide capacity. The health system can already run up to 400 tests per day. UC Davis Health works to expand into a high-volume testing hub with its Roche Diagnostics cobas 6800 robot.


Apr. 16Reporting the first trial of a promising antiviral

Preliminary results emerge from the first small clinical trial of the antiviral therapy remdesivir, conducted at UC Davis Health and hospitals worldwide. Nearly two-thirds of the severely ill, hospitalized COVID-19 patients who received the drug improved, with no new safety concerns. WebMD’s Chief Medical Officer interviews site principal investigator Stuart Cohen about the results, which are published in the New England Journal of Medicine. Larger, controlled trials follow, and remdesivir emerges as one of the most promising in the early field of potential treatments.

UC Davis joins two worldwide COVID-19 clinical studies

UC Davis Health becomes one of 75 sites worldwide evaluating the investigational antiviral remdesivir. With emergency FDA approval, UC Davis clinicians used remdesivir in February to successfully treat the nation’s index case.


Apr. 29Testing begins on a potential COVID-19 vaccine

Biopharmaceutical company Verndari, Inc. announces the start of preclinical testing with the UC Davis’ Mouse Biology Program to evaluate a potential vaccine and dermal patch delivery system for COVID-19.


Apr. 29Plasma transfusions for COVID-19

Two UC Davis Health patients with COVID-19 receive transfusions from a blood donor who recovered from the virus. This is part of a national initiative investigating the potential benefits of convalescent plasma. It’s hoped the treatment may boost a sick patient’s ability to neutralize COVID-19 and its effects.

March 2020


Adjusting to deliver essential non-COVID care

As the main referral center for a 33-county area, UC Davis Medical Center prepares for a potential surge in COVID-19 patients — while also adapting operations to continue essential procedures, such as breast cancer surgeries.

Mar. 11 – The World Health Organization (WHO) declares a global COVID-19 pandemic.


Mar. 13 – The U.S. declares a national emergency.


Mar. 16 – California issues a sweeping stay-at-home order.


Mar. 24 – UC Davis Health sees more than 1,000 patients per day via telehealth video visit, a 5,000% increase in just two weeks.


index patient chest scan
Chest x-rays from the index patient show significant improvement after 14 days of treatment at UC Davis Medical Center.

Mar. 30Sharing lessons from our COVID-19 index case

UC Davis Health clinicians publish a case study about their COVID-19 index patient in the journal Clinical Infectious Diseases. UC Davis hematopathologists reported leukemia-like blood test results from the case. They advised fellow clinicians to order COVID-19 testing instead of cancer screenings for certain symptoms.


Setting state and national COVID-19 standards

UC Davis Health faculty help set comprehensive standards for COVID-19 pandemic-related patient care and workforce safety. Examples:

February 2020


UC Davis Health bedside nurse

Feb. 26 UC Davis treats the first U.S. community spread case of COVID-19

UC Davis Health announces it is treating the first apparent case of COVID-19 acquired by community spread, driving changes to national testing guidelines.


Feb. 29 – The first suspected U.S. death is reported near Seattle.

January 2020


Jan. 22 – UC Davis Health pulls together a working group to begin planning for COVID-19 identification and case management.

December 2019


An outbreak of acute respiratory illness, linked to a novel coronavirus (COVID-19), emerges in China.

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