Gao Fu, director of the Chinese Center for Disease Control and Prevention, speaks during the 2021 China Development Forum at Diaoyutai State Guesthouse on March 20, 2021 in Beijing, China.
Han Haidan | China News Service Getty Images
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 mixing them to get a boost.
Chinese vaccines “do not have very high protection rates,” the director of China’s Disease Control Centers, Gao Fu, said at a conference Saturday in the southwestern city of Chengdu.
Beijing has distributed hundreds of millions of doses abroad as it tries to raise doubts about the effectiveness of the Pfizer-BioNTech vaccine made through the experimental process of messenger RNA or mRNA.
“It is now being formally considered whether we should use different vaccines from different technical lines for the immunization process,” Gao said.
Officials at a press conference on Sunday did not directly answer questions about Gao’s comment or possible changes to official plans. But another CDC official said developers are working on mRNA-based vaccines.
Gao did not answer any phone calls for further comments.
“The mRNA vaccines developed in our country have also entered the stage of clinical trial,” official Wang Huaqing said. He gave no chronology for a possible use.
Experts say the vaccine mix or sequential vaccination can increase effectiveness. Researchers in Britain are studying a possible combination of Pfizer-BioNTech and the traditional AstraZeneca vaccine.
The coronavirus pandemic, which began in central China in late 2019, is the first time the Chinese pharmaceutical industry has played a role in responding to a global healthcare emergency.
Vaccines manufactured by Sinovac, a private company, and Sinopharm, a state-owned company, have made up the majority of Chinese vaccines distributed in several dozen countries, including Mexico, Turkey, Indonesia, Hungary, Brazil and Turkey.
Researchers in Brazil found that the effectiveness of a Sinovac vaccine in preventing symptomatic infections was as low as 50.4%, close to the 50% threshold at which health experts say a vaccine. In comparison, the Pfizer-BioNTech vaccine has been found to be 97% effective.
Health experts say Chinese vaccines are unlikely to be sold in the United States, Western Europe and Japan because of the complexity of the approval process.
A Sinovac spokesman, Liu Peicheng, acknowledged that various levels of effectiveness have been found, but said it may be due to the age of the people in a study, the strain of the virus and other factors.
Beijing has not yet approved any foreign vaccine for use in China.
Gao did not give details about possible changes in strategy, but cited mRNA as a possibility.
“Everyone should consider the benefits that mRNA vaccines can bring to humanity,” Gao said. “We have to follow it carefully and not ignore it just because we already have several types of vaccines.”
Gao had previously questioned the safety of mRNA vaccines. The official Xinhua news agency quoted it as saying in December that it could not rule out negative side effects because they were first used in healthy people.
Chinese state media and popular science and health blogs have also questioned the safety and effectiveness of the Pfizer-BioNTech vaccine.
As of April 2, about 34 million people in China have received the two doses needed for Chinese vaccines and about 65 million have received one, according to Gao.
Sinovac spokesman Liu said the studies consider protection “may be better” if the time between vaccinations is longer than the current 14 days, but gave no indication that it could become a standard practice.