Chinese Covid-19 vaccine far less effective than initially claimed
January 13, 2021 at 10:22
The razor-thin margin for regulatory approval is likely to lead to concern among scientists, given that last week the Butantan institute released partial "clinical efficacy" results celebrating 78% to 100% efficacy in preventing infections.
The state body financed the phase 3 trials of the vaccine, which involved 13,000 health workers across eight Brazilian states.
Joao Doria holds a box of Sinovac's Coronavac vaccine during a news conference on November 19, 2020 in Sao Paulo, Brazil.
The final efficacy rate of the vaccine will be determined by China's drug regulator, the National Medical Production Administration, according to the representative.
The results suggest Coronavac is less effective than alternative vaccines developed by Pfizer-BioNTech and Moderna, which have an efficacy rate of about 95%.
Russia says its Sputnik V vaccine is 91% effective, while the UK's vaccine, developed by Oxford University and AstraZeneca, has an average efficacy of 70%.
Sinovac has signed deals to provide 46 million doses of its Covid-19 vaccine to Brazil, 50 million doses to Turkey and 7.5 million doses to Hong Kong.
It'll also supply 40 million doses of vaccine bulk -- the vaccine concentrate before it is divided into vials -- to Indonesia for local production.
"Since many countries are planning to order, or have already ordered Sinovac's vaccines, it might undermine people's willingness to take them, because people may question the usefulness of the vaccines," Huang said.
When announcing its efficacy results, state-owned Sinopharm did not provide details on its clinical trial data.
Sinopharm's efficacy rate of 79%, for example, is lower than the 86% announced by the United Arab Emirates for the same vaccine in December.
"If people learn about this, they might start to question the safety and efficacy of the Sinovac vaccine, or even other Chinese-made vaccines," Huang said.