China’s Sinovac Biotech defended the safety and efficacy of its experimental COVID-19 vaccine, after researchers in Brazil released late-stage clinical data showing efficacy that would barely scrape the regulatory minimum, writes MedicalBrief.
Reuters reports that the vaccine was just 50.4% effective at preventing symptomatic infections in the Brazilian trial, including data on “very mild” cases, which is barely over the 50% needed for regulatory approval. But researchers stressed that the vaccine is 78% effective in preventing mild cases that needed treatment and 100% effective in staving off moderate to serious cases.
The news prompted Malaysia and Singapore, which have purchase agreements with Sinovac, to say that they would seek more data from the Chinese firm on efficacy rates before they approved and bought supplies.
“These Phase III clinical trial results are sufficient to prove that CoronaVac vaccine’s safety and effectiveness are good around the world,” Sinovac Biotech Chairman Yin Weidong told a news conference. Different countries used vaccines from the same batch in their trials, but the countries don’t have identical testing protocols, he said.
The BBC reports that last month Turkish researchers said the Sinovac vaccine was 91.25% effective, while Indonesia, which rolled out its mass vaccination programme on Wednesday, said it was 65.3% effective. Both were interim results from late-stage trials.
Full Reuters report
Full BBC report