A box of Sinovac Biotech’s CoronaVac SARS-CoV-2 vaccine is exhibited at a media event in Beijing, China, on Thursday, 24 September 2020.
Nicholas Bock | Bloomberg | Getty Images
China’s Sinovac Biotech defended the safety and efficacy of the experimental Covid-19 vaccine on Wednesday after researchers in Brazil released late-stage clinical data showing the efficacy lower than initially announced.
The vaccine was only 50.4% effective in preventing symptomatic infection in a Brazilian trial, including information on the cases where “Not very intense,”; the researchers said on Tuesday.
Last week, they said a vaccine called CoronaVac was 78% effective in “mild to severe” cases.
The news urged Malaysia and Singapore, which had a buying deal with Sinovac, said on Wednesday they would seek further information from Chinese companies on their efficiency rates before approving and purchasing supplies.
“The results of these Phase III clinical trials are sufficient to prove the safety and effectiveness of the CoronaVac vaccine globally,” Sinovac Biotech president Yin Weidong said in a press release.
Different countries used vaccines from the same set in trials. But that country doesn’t have a uniform testing protocol, he said.
Piecemeal disclosures from the Sinovac trial and from other Chinese vaccine studies raise concerns that they are not subject to public scrutiny like the U.S. and European alternatives.
Information from Brazil was released, just as Indonesia ran a vaccination campaign, with President Joko Widodo being the first to administer Sinovac’s CoronaVac.
Malaysia said on Wednesday it would continue its purchasing if the vaccine met the safety and efficacy standards of local regulators.
On Tuesday, Malaysia’s Pharmaniaga Bhd signed a deal with Sinovac to buy 14 million doses of CoronaVac and will later be produced in the country.
Singapore, the only high-income country where Sinovac has entered into the deal, said it would go through official data when Sinovac released the data rather than based on the performance reported so far and then decide whether to approve it.
Thailand, which has ordered 2 million doses of CoronaVac, said it was still on track to receive and administer the vaccine next month. But will ask for more direct information from Sinovac.