China’s top disease control official on Saturday acknowledged that the country’s coronavirus vaccines “don’t have very high protection rates” and that the government is exploring potentially mixing them to bolster their efficacy.
The admission by Gao Fu, the director of the China Centers for Disease Control, comes as Beijing has already distributed hundreds of millions of doses in other countries and has not approved any foreign vaccines for use in China.
“It’s now under formal consideration whether we should use different vaccines from different technical lines for the immunization process,” Gao said at a conference in Chengdu, according to the New York Post.
Yet more than 34 million people have received both of the two doses required by the Chinese vaccines and roughly 65 million people have received one, Gao said.
While researchers in Brazil found a coronavirus vaccine created by Sinovac, a Chinese developer, was just 50.4 percent effective in preventing symptomatic infections, those made by Pfizer and Moderna have been shown to be over 90 percent effective.
Chinese vaccines rely on traditional technology while both the Pfizer and Moderna vaccines used mRNA, a previously experimental technique.
“Everyone should consider the benefits mRNA vaccines can bring for humanity,” Gao said. “We must follow it carefully and not ignore it just because we already have several types of vaccines already.”
His comments come after he previously raised questions about the safety of mRNA vaccines, along with Chinese state media and popular health and science blogs. Gao reportedly said in December that he couldn’t rule out negative side effects from mRNA vaccines as they were being used for the first time on healthy people.
Meanwhile, scientists are studying whether mixing vaccines or sequential immunization may raise efficacy rates, including in Britain where researchers are investigating a possible combination of Pfizer and AstraZeneca vaccines.