CoronaVac 78-percent effective in Brazilian study, lab files for emergency approval

. Jan 07, 2021
Butantan factory producing the CoronaVac in Brazil. Photo: GOVESP Butantan factory producing the CoronaVac in Brazil. Photo: GOVESP

The Chinese-made CoronaVac posted 78-percent efficacy against the coronavirus during final studies with Brazilian patients, according to newspaper Folha de S.Paulo. The vaccine, produced by the Beijing-based lab Sinovac Biotech, is being tested in Brazil by São Paulo’s Butantan Biological Institute.

In the wake of the news, Butantan issued a request to federal health regulatory agency Anvisa for the emergency approval of CoronaVac. Emergency clearance would allow the vaccine to be administered to pre-defined population groups and for a restricted amount of time.

The 78 percent rate refers to mild Covid-19 cases — while moderate and severe ones were completely avoided among trial participants. The data has been revised by a panel of international experts.

CoronaVac phase 3 trials in Brazil included 13,000 volunteers who took two jabs over a space of 14 days. All study participants were health workers, hailing from eight different states. A reported 220 volunteers were subsequently infected with the coronavirus — but no deaths were recorded.

The politics of the CoronaVac

The Chinese vaccine has been subject to intense politicization by both São Paulo Governor João Doria — who intends to use a successful vaccination program as a stepping stone to the presidency — and President Jair Bolsonaro, who wants to prevent any politician from building a competitive challenge to his re-election in 2022.

The rift between the two led to speculation around potential political interference by the government in Anvisa — which is tasked with approving vaccines before distribution.

On Wednesday, Mr. Doria presented his statewide plan to start administering the CoronaVac to São Paulo citizens from January 25 on — leading the federal government to scramble in order to put forward its own inoculation program.

This is a developing story and will be updated as new information surfaces.

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Gustavo Ribeiro

An award-winning journalist, Gustavo has extensive experience covering Brazilian politics and international affairs. He has been featured across Brazilian and French media outlets and founded The Brazilian Report in 2017. He holds a master’s degree in Political Science and Latin American studies from Panthéon-Sorbonne University in Paris.

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