The effectiveness of Chinese coronavirus vaccines is low and the government is considering combining them, the top authority of the Chinese disease control agency said on Sunday, in an unusual official admission of the weakness of Chinese vaccines. .
Chinese drugs “do not have very high protection rates,” the director of the Chinese Centers for Disease Control, Gao Fu, told a conference on Saturday in the southwestern city of Chengdu.
Beijing has distributed hundreds of millions of doses in other countries and tried to dispel doubts about the effectiveness of Western vaccines.
“It is now officially considered whether we should use different vaccines of different technical lines for the immunization process,” Gao said.
Beijing has not yet approved any foreign vaccine for use in China.
Gao did not give details of possible changes in strategy, but mentioned messenger RNA, a previously experimental technology used by Western vaccine manufacturers, while Chinese pharmaceuticals employed established techniques.
“Everyone should consider the benefits that messenger RNA vaccines can bring to humanity,” he said. “We have to follow it carefully and not ignore it just because we already have several types of vaccines.”
Gao had in the past questioned the safety of messenger RNA vaccines. The official Xinhua news agency quoted statements in December in which it said it could not rule out negative side effects because it was the first time vaccines were used in healthy people.
Officials who gave a press conference on Sunday did not directly answer questions about Gao’s comments or possible changes to official plans. But another member of the disease control center noted that he was working on messenger RNA vaccines.
“Messenger RNA vaccines developed in our country have also entered the phase of clinical trials,” said official Wang Huaqing, who did not give deadlines for their possible distribution.
Chinese state media and popular science and health blogs have also questioned the safety and effectiveness of the Pfizer vaccine, which uses messenger RNA.
As of April 2, about 34 million people had received the required two doses of Chinese vaccines, while about 65 million people had already received a dose, Gao said.
Experts point out that mixing vaccines, or sequential immunization, can boost effectiveness rates. Several trials in different parts of the world are studying the effect of mixing vaccines or administering a reminder dose after a long period of time. Researchers in Britain are studying a possible combination of Pfizer and AstraZeneca vaccines.
The coronavirus pandemic, which began in central China in late 2019, has raised the first occasion in which the Chinese pharmaceutical industry has played a role in responding to a global health emergency.
Vaccines manufactured by two state-owned pharmaceuticals, Sinovac and Sinpopharm, have been exported to 22 countries, including Mexico, Turkey, Indonesia, Hungary, Brazil and Turkey, according to the Foreign Ministry.
Researchers in Brazil concluded that the effectiveness of a Sinovac vaccine in preventing symptomatic infections was only 50.4%, close to the 50% threshold at which experts find a vaccine useful. In comparison, the Pfizer-BioNTech vaccine has an effectiveness of 97%.
Health experts see it unlikely that Chinese vaccines will be sold in the United States, Western Europe and Japan because of the complexity of the legal approval process.