Chinese company says its new vaccine 82% effective against serious infections

BEIJING • A vaccine from China's Chongqing Zhifei Biological Products has shown 82 per cent effectiveness against serious Covid-19 infections, boosting the nation's efforts to immunise its population.

In late-stage clinical trials, the vaccine - dubbed ZF2001 - has been shown as 92.93 per cent effective against the Alpha coronavirus variant and almost 78 per cent against the more-infectious Delta version, the company said in an exchange filing on Friday.

It did not say if those two figures were just for serious illness or all symptomatic infections including mild cases. None of the people who received the shot entered critical care or died, it said.

The results were based on an interim analysis of 221 infections in the study of 28,500 people.

Zhifei's shot is the fifth developed in China that has been validated in large clinical trials done in places still battling outbreaks.

The vaccine was co-developed with the Institute of Microbiology at the Chinese Academy of Sciences, the country's top scientific research organ, and the efficacy against the Alpha variant appears to be one of the highest among all Chinese Covid-19 vaccines so far.

Zhifei launched phase three trials - the final study required before gaining authorisation - for the experimental shot last December in Uzbekistan, and kicked off testing in Pakistan in February.

The vaccine is also being tested in Ecuador and Indonesia.

China approved the shot for emergency use on March 10, and it is now among several being administered across the vast nation.

The recombinant protein vaccine uses a similar technology as Novavax's shot which relies on purified components of the virus and does not need the same levels of biosecurity as other inactivated Covid-19 vaccines.

The Novavax vaccine boasts 90 per cent efficacy against symptomatic Covid-19 but appeared to be far less effective in an earlier study against the Beta variant.

BLOOMBERG