A senior Chinese official said that the country\u2019s vaccines may need to be administered in greater doses or in concert with other shots because of their low overall effectiveness.<\/p>\n
The comments on Saturday by Gao Fu, the director of China\u2019s disease control center, suggest that China and more than 60 countries that have approved Chinese vaccines could need to adjust their distribution programs. The widespread distribution of Chinese vaccines means that any changes could potentially affect hundreds of millions of people or more.<\/p>\n
Possible steps to boost effectiveness of Chinese vaccines include changing the amount of vaccine given, the number of shots, the time between shots or the type of vaccines given, Mr. Gao said.<\/p>\n
He also praised the possibilities offered by messenger RNA. That technology is used in the Moderna and Pfizer-BioNTech vaccines but not in any of the vaccines thus far approved in China.<\/p>\n
Officials in Brazil said in January that the efficacy rate for the CoronaVac vaccine from the Beijing-based company Sinovac was just over 50 percent. By comparison, Moderna and Pfizer-BioNTech were found to be 90 percent effective in real world conditions, researchers said last month.<\/p>\n
Last month the distributor in the United Arab Emirates of vaccines from China\u2019s Sinopharm said it was offering a third dose in addition to the standard two-dose regimen for a \u201cvery small number\u201d of people who were \u201cnot really responsive\u201d to the vaccine.<\/p>\n