A coronavirus vaccine developed by China’s Sinovac Biotech was 78% effective in a late-stage Brazilian trial with no severe Covid-19 cases, researchers said on Thursday, although a lack of data details stirred calls for more transparency, Reuters reports.
The trial results, closely watched by developing countries counting on the vaccine to begin mass inoculations to help end a raging pandemic, was below preliminary findings from Turkish researchers and lacked detailed data provided on US and European vaccines.
The director of Brazilian biomedical center Butantan, Sinovac’s research and production partner, said detailed results were being submitted to health regulator Anvisa as part of a request for emergency use of the vaccine.
“One thing is a presentation at a news conference. It’s something else to get the data and analyze it, which is what Anvisa will do,” said Cristina Bonorino, who sits on the scientific committee of the Brazilian Immunology Society. “If it’s what they say, that’s 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 struck supply deals with Sinovac.
Although CoronaVac’s efficacy falls short of 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% benchmark set by global health authorities for vaccines in development early in the pandemic, given the urgent need.