A senior Chinese official said the country’s vaccines may need to be administered in larger doses or in conjunction with other shots, due to their low efficacy.
The comments made on Saturday by Gao Fu, the director of China’s disease control center, suggest that China and more than 60 countries that have approved Chinese vaccinations need to adjust their distribution programs. The widespread distribution of Chinese vaccines means that changes could potentially affect hundreds of millions of people or more.
Possible steps to increase the 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, said Mr. Gao said.
He also praised the possibilities that the messenger RNA offers. The technology is used in the Moderna and Pfizer BioNTech vaccines, but not in any of the vaccines approved so far in China.
In an interview on Sunday with the Global Times newspaper, which is led by the Communist Party, Mr. Gao said his comments had been misunderstood earlier, and that discussion on how to improve vaccine efficacy should be a universal question.
“The protection rates of all vaccines in the world are sometimes high and sometimes low,” he said. “How to improve their efficiency is a question that needs to be considered by scientists around the world.”
Officials in Brazil said in January that the effectiveness rate for the CoronaVac vaccine from Beijing-based company Sinovac was just over 50 percent. By comparison, Moderna and Pfizer-BioNTech have been found to be 90 percent effective in real-world conditions, researchers said last month.
Last month, the United Arab Emirates distributor of vaccines from China, Sinopharm, said it was offering a third dose in addition to the standard two-dose regimen for a ‘very small number’ of people who ‘do not really respond’ to the vaccine.