A preliminary study made with over 43,000 people over 70 years old in São Paulo, Brazil, shows that Sinovac‘s CoronaVac has a 71.4% effectiveness against death caused by the COVID-19’s Gamma variant (also known as P.1). However, the research, not yet peer-reviewed, also suggests that CoronaVac’s effectiveness may decline among seniors aged 80 or more.
In Brazil, CoronaVac is produced by the Butantan Institute, in a partnership with Sinovac, and it is one of the most used vaccines against COVID-19 in the country, especially among the elderly since it was the first vaccine to be available for immunization in Brazil.
The study was conducted by the Vebra COVID-19 group, which brings together Brazilian and foreign researchers from institutions such as Fiocruz, Incor, and the Global Health Institute of Barcelona to assess the effectiveness of vaccines used in Brazil. It was published on the MedRxiv platform on Wednesday and is still in the pre-print phase.
Furthermore, although the average protection against death caused by the variant among the elderly is 71.4%, it varies from 87.1% (in the group from 75 to 79 years old) to 49.9% ( 80 years or more).