The efficacy of a Sinovac coronavirus vaccine has been determined by researchers to be only 50.4 percent.
In a rare admission of the weakness of Chinese coronavirus vaccines, the country’s top disease control official says their effectiveness is low and the government is considering combining them to boost them.
Chinese vaccines “do not have very high levels of protection,” said director of the China Centers for Disease Control, Gao Fu, at a conference Saturday in the southwestern city of Chengdu.
Beijing has distributed hundreds of millions of doses in other countries.
“It is now formally considered whether we should use different vaccines from different technical lines for the immunization process,” said Gao.
Researchers in Brazil have determined that the effectiveness of a coronavirus vaccine from Sinovac, a Chinese developer, in preventing symptomatic infections is only 50.4 percent. In comparison, the Pfizer-BioNTech vaccine has been shown to be 97 percent effective.
Beijing has yet to approve foreign vaccines for use in China, where the coronavirus emerged in late 2019.
Gao did not detail possible changes in the strategy, but mentioned mRNA, a previously experimental technique used by some Western vaccine developers, while the Chinese drug makers used traditional technology.
“Everyone should consider the benefits mRNA vaccines can have for mankind,” said Gao. “We have to monitor it carefully and not ignore it just because we already have different types of vaccines.”
mRNA
Gao previously asked questions about the safety of mRNA vaccines. He was quoted by the official Xinhua news agency as saying in December that he could not rule out negative side effects because they were first used in healthy people.
Chinese state media and popular health and science blogs have also questioned the safety and effectiveness of the Pfizer-BioNTech vaccine, which uses mRNA.
On April 2, about 34 million people received the two doses needed for Chinese vaccines and about 65 million received one, Gao said.
Experts say mixing vaccines or sequential immunization can increase effectiveness. Testing around the world has focused on mixing vaccines or giving a booster shot after an extended period of time.
Researchers in Great Britain are studying a possible combination of the Pfizer-BioNTech and AstraZeneca vaccines.