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 viruses, while other countries’ offerings, including those by Pfizer-BioNTech and Moderna, rely on a new technique that uses messenger RNA (mRNA) to stimulate an immune response.