A coronavirus vaccine developed by China’s Sinovac Biotech was 78% effective in a late-stage Brazilian trial with no serious Covid-19 cases, researchers said Thursday, although a lack of data details sparked calls for more transparency, Reuters reports.
The research results, closely watched by developing countries expecting the vaccine to initiate massive vaccinations to end a raging pandemic, were lower than the preliminary findings of Turkish researchers and detailed data on US and European vaccines was lacking.
The director of Brazil’s Biomedical Center Butantan, Sinovac’s research and manufacturing partner, said detailed results were submitted to health regulator Anvisa as part of a request for emergency use of the vaccine.
“One thing is a presentation at a press conference. It’s another thing to collect and analyze the data, and that’s what Anvisa will do, ”said Cristina Bonorino, a member of the scientific committee of the Brazilian Immunology Association. “If it is what they say, that is an excellent result,” she added.
Brazil and Indonesia, which have the most Covid-19 cases in Latin America and Southeast Asia, respectively, are preparing to roll out the vaccine, called CoronaVac, this month. Turkey, Chile, Singapore, Ukraine and Thailand have also entered into supply agreements with Sinovac.
Although the efficacy of CoronaVac lags behind the 95% success rate of vaccines from Moderna Inc or Pfizer Inc with partner BioNTech SE, it is easier to transport and can be stored at normal refrigerator temperatures.
The 78% efficacy rate is also well above the 50% to 60% standard set by the global health authorities for vaccines under development at the start of the pandemic, given the urgent need.