China's CoronaVac vaccine is the "the safest among the vaccines currently tested across the world," a top official at Brazil's leading biomedical research center said Wednesday, without releasing data to support the claim.
Butantan Institute director Dimas Covas made the comments at a news conference in São Paulo Wednesday, saying contractual obligations prevented him from speaking publicly about the vaccine’s efficacy.
The vaccine is currently in late-stage clinical trials in Brazil. The trials are being conducted by Chinese vaccine company Sinovac Biotech and the Butantan Institute.
Covas said all data collected in Brazil's trial was sent to China for Sinovac to review. Trial data will be released in time for a global media event in January.
Covas also said that while he could not discuss the findings of the trial, CoronaVac is effective enough to request emergency use authorization in both China and Brazil, signaling the vaccine is at least 50% effective.
The Pfizer-BioNTech and Moderna vaccines approved for emergency use in the United States are both up to 95% effective.
On Thursday, Brazil will receive 5 million doses of the CoronaVac vaccine, Covas said.