COVID-19 Pandemic Timeline

The US Food and Drug Administration issued an emergency use authorization for remdesivir, an antiviral drug shown in clinical trials to shorten recovery time for hospitalized COVID-19 patients.

Image source: Remdesivir

The United States launched Operation Warp Speed, a public-private partnership investing billions of dollars to accelerate the development, manufacturing, and distribution of COVID-19 vaccines, therapeutics, and diagnostics.

Image source: Operation Warp Speed

Researchers in the United Kingdom announced that the inexpensive steroid dexamethasone reduced mortality among hospitalized COVID-19 patients requiring oxygen or ventilation, becoming the first treatment proven to save lives during the pandemic.

Image source: Dexamethasone

Pfizer and BioNTech announced interim results showing their mRNA vaccine candidate was more than 90% effective at preventing symptomatic COVID-19, marking a landmark moment in vaccine science and offering hope of ending the pandemic.

Image source: Pfizer–BioNTech COVID-19 vaccine

The United Kingdom granted emergency authorization to the Pfizer-BioNTech vaccine, becoming the first Western nation to approve a COVID-19 vaccine and beginning mass inoculation days later.

Image source: COVID-19 vaccination in the United Kingdom

Margaret Keenan, a 90-year-old British woman, received the first authorized COVID-19 vaccination outside a clinical trial, launching the largest mass vaccination campaign in history as other nations followed suit.

Image source: COVID-19 vaccine

The US Food and Drug Administration issued an emergency use authorization for the Pfizer-BioNTech vaccine, with the first American doses administered on December 14, 2020, to healthcare workers and long-term care residents.

Image source: Food and Drug Administration

The COVAX initiative, co-led by Gavi, the WHO, and CEPI, delivered its first doses to Ghana, aiming to ensure equitable global access to COVID-19 vaccines for low- and middle-income countries.

Image source: COVAX

The FDA granted emergency use authorization to the Johnson & Johnson (Janssen) vaccine, the first single-dose COVID-19 vaccine available in the United States, simplifying logistics for hard-to-reach populations.

Image source: Janssen COVID-19 vaccine

The World Health Organization granted emergency use listing to China's Sinovac CoronaVac vaccine, expanding access to vaccines in developing countries and adding to the growing global arsenal of approved shots.

Image source: CoronaVac

The FDA authorized additional doses of mRNA vaccines for certain immunocompromised individuals, the first step toward broader booster campaigns as evidence emerged of waning immunity over time.

Image source: Pfizer–BioNTech COVID-19 vaccine

The FDA authorized Pfizer's Paxlovid and Merck's molnupiravir, the first oral antiviral pills for treating COVID-19, offering a convenient outpatient treatment option to reduce hospitalizations and deaths.

Image source: Nirmatrelvir/ritonavir

A more transmissible variant of SARS-CoV-2, later named Alpha, was first detected in southeast England in late 2020, prompting renewed restrictions and international concern about variant spread.

A catastrophic second wave fueled by the Delta variant overwhelmed India's healthcare system, with record daily deaths, oxygen shortages, and mass cremations drawing international aid and attention.

The postponed Tokyo Olympics finally took place in 2021 without spectators at most venues, held under strict bubble protocols as Japan battled a Delta-driven wave of infections.

The WHO designated the Mu variant as a variant of interest, joining Lambda, as scientists tracked multiple emerging strains for signs of increased transmissibility or immune escape.

The WHO classified the Omicron variant, first reported by South Africa, as a variant of concern due to its unusually large number of mutations, triggering travel bans and intense scientific scrutiny worldwide.

The hyper-transmissible Omicron variant drove record-shattering case counts around the world, infecting millions daily, straining workforces and health systems, yet generally causing less severe illness per infection than earlier variants.