Covid: China says vaccine makers upgraded shots to fight Omicron

Early lab studies have shown inactivated vaccines developed by Chinese companies Sinovac and Sinopharm elicited less protective antibodies against the omicron variant than mRNA vaccines from Pfizer

Chinese officials said vaccine makers have upgraded their Covid-19 vaccines against the omicron variant and other strains but new shots will be validated for safety and efficacy before they can be rolled out.

Widely-used inactivated shots in the country have been tweaked to fight up to three variants, including omicron and the preceding predominant delta strain, according to Zheng Zhongwei, an official who oversees Covid vaccine development at the National Health Commission. Another protein subunit shot targeting four variants is seeking approval for human testing overseas, he said.

“We share the urgent wish of everybody to use omicron target vaccines,” Zheng said at a briefing in Beijing Saturday. “As we expedite development of omicron vaccine, we consistently make safety and efficacy our No. 1 priority.”

He said omicron’s ability to evade immunity induced by existing vaccines has been proved in studies to be partial, meaning that receiving full vaccination still effectively reduces risk of hospitalization, severe disease and death caused by the variant while getting booster shots can reduce the risk of breakthrough infections.

Early lab studies have shown inactivated vaccines developed by Chinese companies Sinovac Biotech Ltd. and Sinopharm elicited less protective antibodies against the omicron variant than mRNA vaccines from Pfizer Inc. or Moderna Inc, even after a booster shot. That led to some researchers recommending people who were previously fully inoculated with the inactivated vaccine to boost their immunity with a more potent shot.

China also has allowed people to get a different type of Covid booster if they received the inactivated ones. The country is also developing an mRNA vaccine and has obtained data on protection against omicron by mixing different shots in overseas trials, Zheng said, without providing further details.

Omicron’s weaker virulence and China’s mass vaccination drive -- nearly 90% of its 1.4 billion people are fully vaccinated and more than a third have gotten boosters -- have lead to 95% of those infected showing only mild or no symptoms in a nationwide outbreak that has become the worst for the country in more than two years.

China on Saturday reported the deaths of two people after contracting Covid. Both are over 60 years old and have underlying diseases, with one of them unvaccinated. Officials said both patients’ Covid infections have been mild and their underlying diseases killed them.
 

Chinese officials have been urging the country’s elderly population to get vaccinated. While some 80% of those over 60 have been fully vaccinated, the share drops to around half for people aged 80 or above, a group most vulnerable to the virus and at high risk of getting severe diseases and death without vaccine protection.

Elderly people account for more than 90% of deaths in the Covid outbreak in Hong Kong, with unvaccinated people more than 30 times more likely to die than the vaccinated, according to Zheng.