Top health official: Effectiveness of Chinese vaccines ‘not high’

The head of the Chinese Center for Disease Control and Prevention conceded that the efficacy of Chinese coronavirus vaccines is “not high” and that they may require improvements, marking a rare admission from a government that has staked its international credibility on its doses.

The comments on Saturday from George Gao come after the government has already distributed hundreds of millions of doses to other countries, even though the rollout has been dogged by questions over why Chinese pharmaceutical firms have not released detailed clinical trial data about the vaccines’ efficacy.

China has struck deals to supply many of its allies and economic partners in the developing world and boasted that world leaders - including in Indonesia, Pakistan and the United Arab Emirates - have taken the shots.

There have been signs that some countries remain skeptical: The UAE recently experimented with administering three shots of the Chinese Sinopharm vaccine, instead of two, over reports of low numbers of antibodies produced in some people, while Singapore has stockpiled but not usedSinovac shots.

China is “formally considering” options to change its vaccines to “solve the problem that the efficacy of the existing vaccines is not high,” Gao said at a conference in Chengdu.

Gao added that one possibility was to adjust the dosage or increase the number of doses. He said another option was to mix vaccines that are made with different technologies, in an apparent admission that China needs to develop messenger RNA vaccines using the revolutionary genetic technology that Western countries have harnessed.

Gao’s remarks, which appeared inadvertent and quickly spread through Chinese social media on Saturday before being mostly censored, marked a departure from the rosy assessments of Chinese-made vaccines by the government. By Sunday, Internet users were intentionally misspelling words in their posts while discussing Gao’s comments to keep them from being removed.

Sinopharm and Sinovac use a conventional method of producing vaccines that contains inactivated germs, while other countries’ offerings, including those by Pfizer-BioNTech and Moderna, rely on a newfangled technique that uses messenger RNA (mRNA) to stimulate an immune response.