- The vaccine turned out to be just 50.38 percent effective against COVID-19 in late-stage trials.
- Sinovac commented that the earlier rates included only volunteers who had mild to severe cases of coronavirus.
On Tuesday, Brazilian researchers announced that China’s Sinovac vaccine was far less effective than originally touted. As per research, the vaccine turned out to be just 50.38 percent effective against COVID-19 in late-stage trials, nearly 30 percentage points lower than initial data showed.
Previously, the Butantan Institute in São Paulo had initially announced that late-stage trials had found the CoronaVac vaccine to be between 78 percent and 100 effective. However, several scientists accused the trial’s organizers of misleading the public. The organizers had disclosed that the cases were separated into six categories including, asymptomatic, very mild, mild, two levels of moderate, and severe. They mentioned that the earlier rates included only volunteers who had mild to severe cases of coronavirus.
Reportedly, the vaccine just meets the 50 percent threshold required for approval by Brazilian regulators and the World Health Organization. Commenting on the situation, Bhutantan mentioned that when data from all volunteers are accounted for, including volunteers who contracted very mild symptoms and required no medical assistance, the total efficacy rate dropped to 50.38 percent.
However, since CoronaVac was 100 percent effective in preventing severe cases, the experts suggested that it could be stored inexpensively in a regular refrigerator. While Brazil’s health regulator is reviewing a request for emergency use of CoronaVac, Sao Paulo authorities plan to begin vaccinations on January 25.