“Protection rates for existing vaccines are not high,” Gao Fu, director of the Chinese Center for Disease Control and Prevention, told a conference in the southwestern city of Chengdu on Saturday.
He listed two options to solve the problem: one is to increase the number of doses or adjust the dose or the interval between photos; the other is the mixing of vaccines developed from different technologies.
China has positioned itself as a leader in the development and distribution of the Covid-19 vaccine, promoting and supplying its vaccines to countries around the globe, including Indonesia, Zimbabwe, Turkey and Brazil.
“More than 60 countries have approved the use of the Chinese vaccine. The safety and efficacy of the Chinese vaccine are widely recognized by various countries,” Chinese Foreign Minister Wang Yi told a news conference in March.
However, the relatively low efficacy rate of Chinese vaccines could undermine credibility and affect so-called Beijing vaccine diplomacy.
The two pharmaceutical companies that supply most of the Chinese Covid-19 vaccines to the world have not published comprehensive clinical trial data in medical journals on the effectiveness of their vaccines. But, from the interim results announced by the companies, their effectiveness remains far behind the new type of vaccines developed in the West that use mRNA to trigger an immune response.
The CoronaVac vaccine developed by Sinovac, a private company, has been shown to have an efficacy rate of only 50.4% in clinical trials in Brazil. Another trial in Turkey showed that it was 83.5% effective. Sinopharm, the state, said its two vaccines have efficacy rates of 79.4% and 72.5%.
In comparison, Pfizer-BioNTech and Moderna vaccines have efficacy rates of 97% and 94%, respectively.
In this regard, Gao’s comments on the relatively low effectiveness of Chinese vaccines stated only a well-known fact – but it was the first time a senior Chinese official publicly acknowledged it.
“What struck me most was that the suggestion of relatively low efficacy rates for Chinese vaccines seems to be a departure from what the Chinese state and social media have said. The official narrative describes Chinese vaccines as both safe and secure. Yanzhong Huang, a senior member of the Foreign Relations Council, who posted Gao’s speech on Twitter over the weekend.
As Gao’s comments gained attention on social media and became international headlines, Chinese censors quickly shattered online discussions, and the state media quickly launched an interview with Gao to withdraw his comments.
“The protection rates of all vaccines in the world are sometimes high and sometimes low. How to improve their effectiveness is a question that needs to be considered by scientists around the world,” Gao said.
Huang, China’s public health expert, said the rapid repudiation of the Global Times suggested that the Chinese authorities would not tolerate any challenge to their official narrative.
“Gao’s remarks were just an occasional aberration,” he said.
Additional reporting by Reuters.