CoronaVac

CoronaVac, also known as the Sinovac COVID-19 vaccine, was a whole inactivated virus SARS-CoV-2 vaccine developed by Sinovac and extensively deployed globally to control the COVID-19 pandemic. Its use was highest in low- and middle-income countries. In January 2024, Sinovac confirmed that production of CoronaVac had been discontinued. Clinical trials have demonstrated that a standard two-dose regimen provides moderate efficacy against symptomatic COVID-19, ranging from about 50% to 83% depending on population and circulating viral variants, with more robust protection observed against severe disease, hospitalization, and death. Although most adverse reactions are mild and serious vaccine-related events are rare, the vaccine’s immune protection against symptomatic infection wanes over time, especially in the context of emerging variants such as Omicron, leading to recommendations for booster doses to sustain immunity and reduce severe outcomes. Overall, CoronaVac’s safety and efficacy profile in preventing severe COVID-19 have contributed to its use in vaccination programs, particularly in regions with limited access to mRNA vaccines. On 1 June 2021, the World Health Organization (WHO) validated CoronaVac for emergency use. Sinovac subsequently signed agreements to supply 380 million doses to COVAX. By July 2021, CoronaVac was the most widely used COVID-19 vaccine globally, with about 943 million doses delivered. As of 14 October 2021, it remained the vaccine with the highest number of doses administered worldwide.