CoronaVac
CoronaVac, also known as the Sinovac COVID-19 vaccine,[3] is a whole inactivated virus COVID-19 vaccine developed by the Chinese company Sinovac Biotech.[4][5] It was phase III clinically trialled in Brazil,[6] Chile,[7] Indonesia,[8] the Philippines,[9] and Turkey[10] and relies on traditional technology similar to other inactivated-virus COVID-19 vaccines, such as the Sinopharm BIBP vaccine, another Chinese vaccine, and Covaxin, an Indian vaccine.[11] CoronaVac does not need to be frozen, and both the final product and the raw material for formulating CoronaVac can be transported refrigerated at 2–8 °C (36–46 °F), the temperatures at which flu vaccines are kept.[12]
Vaccine description
A real-world study of tens of millions of Chileans who received CoronaVac found it to be 66% effective against symptomatic COVID-19, 88% effective against hospitalization, 90% effective against ICU admissions, and 86% effective against deaths.[13] In Brazil, after 75% of the population in Serrana, São Paulo, received CoronaVac, preliminary results show deaths fell by 95%, hospitalizations by 86%, and symptomatic cases by 80%.[14][15] In Indonesia, real-world data from 128,290 healthcare workers showed 94% protection against symptomatic infection by the vaccine, beating results in clinical trials.[16]
Phase III results from Turkey, published in The Lancet, showed an efficacy of 84% based on 10,218 participants in the trials.[17][18] Phase III results from Brazil previously showed 50.7% efficacy in preventing symptomatic infections and 83.7% effectiveness in preventing mild cases needing treatment. Efficacy against symptomatic infections increased to 62.3% with an interval of at least 21 days between the doses.[19]
CoronaVac is being used in vaccination campaigns in various countries in Asia,[20][21][22] South America,[23][24][25] Central America,[26][27][28] and Eastern Europe.[29][30][31] By April 2021, Sinovac had a production capacity of 2 billion doses per year.[32] It was manufactured at several facilities in China,[32] with overseas manufacture planned for Brazil in September 2021[33] and eventually Egypt[34] and Hungary.[35]
On June 1, 2021, the World Health Organization (WHO) validated the vaccine for emergency use.[36][37] Sinovac has signed purchase agreements for 380 million doses from COVAX.[38] As of July 2021, CoronaVac was the most widely used COVID-19 vaccine in the world, with 943 million doses delivered.[39]
As of October 14, 2021, CoronaVac is the COVID-19 vaccine with the most doses administered worldwide.[40]
It was reported in December 2021 that a study jointly conducted by the LKS Faculty of Medicine, The University of Hong Kong (HKUMed), and the Faculty of Medicine, The Chinese University of Hong Kong (CU Medicine), showed that a third dose of the Comirnaty vaccine given to those who received two doses of either Comirnaty or CoronaVac provided protective levels of measured antibodies against the Omicron variant of SARS-CoV-2. Three doses of CoronaVac, however, did not provide adequate levels of protective antibodies by the same measure,[41] in direct contradiction to claims made by the vaccine manufacturer.[42][43]
In October 2022, a Hong Kong study found that two doses of CoronaVac provided protection of only 64% to 75% for older adults. However, an extra booster or a third dose of CoronaVac was able to raise the level of protection against COVID-19 to about 98%.[44]
In January 2024, Sinovac confirmed that it had discontinued production of CoronaVac.[45]
Society and culture
Economics
As of 7 July 2021, CoronaVac is the most widely used COVID-19 vaccine in the world, with 943 million doses delivered globally.[39] In July, Sinovac signed advanced purchase agreements with GAVI to supply COVAX with 50 million doses in the third quarter of 2021 and up to a total of 380 million doses by the first half of 2022.[117][118]