Sinovac Covid-19 vaccine has been shown to be effective in studies in Brazil

SÃO PAULO – Covid-19 vaccine from Sinovac Biotech Ltd., which scientists hope can help fight the pandemic in the developing world, has exceeded the 50% threshold for efficacy in late-stage studies in Brazil, which it means regulators can give it the green light to use, said people involved in its development.

Brazil is the first country to complete phase 3 studies of the Chinese company’s CoronaVac vaccine, which is also being tested in Indonesia and Turkey. With Covid-19 largely under control in China, vaccine developers in the country have had to conduct clinical trials abroad.

People involved in the Brazilian studies, which completed phase 3 last week, told The Wall Street Journal that the results showed CoronaVac at an effective rate of more than 50%, the threshold for a vaccine to be considered viable by international scientists. . People refused to provide any additional information. But scientists looking to develop the vaccine say it is expected to be comparable to other Covid-19 vaccines that have been shown to be 95% effective in studies.

“Everyone is hoping for an efficiency rate of over 90%,” said Domingos Alves, a professor at Ribeirão Preto Medical School in São Paulo, which specializes in health data analysis. “The results of the first phases of the tests were very good.”

Brazil’s Butantan Institute, a research center backed by the São Paulo state government that tested CoronaVac, is set to announce the vaccine’s effectiveness rate on Wednesday. Butantan said on Monday it considered any information given at this time about the vaccine’s effectiveness to be “mere speculation”.

São Paulo Governor João Doria has said he intends to vaccinate the entire state, which hosts about a fifth of Brazil’s population, by the end of July – almost a year earlier than the federal government promised to vaccinate the rest of Brazil’s population.

Ipanema Beach in Rio de Janeiro on Sunday.


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Doria said the results of the CoronaVac phase 3 tests will be presented to Chinese and Brazilian regulators on Wednesday, adding that the state of São Paulo intends to start administering the vaccine on January 25th.

Butantan, which began producing the Sinovac vaccine in Brazil this month, has agreed with the Chinese private company to become a distributor for CoronaVac in Latin America. In May, Butantan plans to begin transporting the vaccine to Argentina, Bolivia, Colombia, Honduras, Peru and Uruguay, Butantan director Dimas Covas said in an interview.

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Write to Samantha Pearson at [email protected] and Luciana Magalhaes at [email protected]

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