China National Pharmaceutical Group Corp., or Sinopharm, is evaluating results of overseas phase three clinical trials to determine if a booster shot may be necessary, according to a company executive.
Sinopharm has been testing the antiviral mutation capacity of vaccines already on the market in China, such as the inactivated vaccine produced by Sinopharm, to see whether the virus mutation will influence efficacy, according to Zhang Yuntao, vice president and chief scientist of China National Biotec Group, a Sinopharm subsidiary, said at a news conference.
Two Sinopharm inactivated vaccines were used in a crossover trial on strains found in South Africa and the U.K., as well as more than 10 strains found in China, using the serum from phase two and three clinical trials in China and abroad, he said.
The findings demonstrated neutralizing antibodies developed by the two inactivated vaccines effectively neutralized these strains.
Concerns that emerging variants of the new coronavirus may weaken the safety of vaccines designed against older strains have prompted regulators and vaccine developers to explore whether booster doses are needed.
Gao Qiang, general manager of Sinovac Biotech Ltd., another manufacturer of vaccines, said Sinovac had also conducted studies on the efficacy of its CoronaVac treatment against variant strains in several countries.
Antibodies caused by Sinovac's vaccine decreased in a variant identified in South Africa while the effect against a variant found in Britain remained identical to that against the older Wuhan variant.
China's National Health Commission said the country had administered more than 100 million doses as of Saturday. As of Friday, the country's global supply of COVID-19 vaccines had exceeded 100 million doses.
Sinopharm's inactivated vaccine has been used in 50 countries and regions around the world. According to Zhang, the population sample size and large scale completely demonstrate the inactivated vaccine's broad spectrum effect.
