Brazilian researchers testing China’s Synovac vaccine said on Tuesday that full data showed it to be 50.38% effective compared to Kovid-19 in late-stage trials, about 30 percent less than previously announced, because Concerns increase over the transparency of the study.
Sao Paulo-based Butanan Institute said last week that late-stage trials showed the Coronavac vaccine to be effective between 78% and 100%, providing total protection against severe cases of the disease.
However, after mounting pressure from scientists, some of whom accused the trial organizers of misleading the public, Butanton said those rates included only volunteers who faced serious cases of Kovid-19. When data from all volunteers are considered, including “very mild” cases of Kovid-19 and not requiring medical assistance, the overall efficacy rate is 50.38%, Buttan said on Tuesday.
Despite having one of the lowest efficacy rates for any new coronovirus vaccine, Coronavac is still more effective than some flu vaccines and can be stored inexpensively in a simple refrigerator, which makes it available for developing countries. Makes a viable option, the Department of Public Health said.
However, the piece of Coronavac’s efficacy rate and the unconventional announcement, which was to be announced earlier last month, are at risk of damaging the reliability of a vaccine that many Brazilians are already reluctant to take, doctors said.