BEIJING (BLOOMBERG) - A vaccine from China's Chongqing Zhifei Biological Products Co showed 82 per cent effectiveness against serious Covid-19 infections, boosting the country's efforts to immunise its vast population.
In late-stage clinical trials, the vaccine - dubbed ZF2001 - has been shown as 92.93 per cent effective against the Alpha variant and almost 78 per cent against the more-infectious Delta version, the company said in an exchange filing Friday (Aug 27).
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 number of infections in the study of 28,500 people.
Zhifei's shot is the fifth developed inside China that has been validated in a 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 Alpha variant appears to be one of the highest among all Chinese Covid-19 vaccines so far.
Zhifei launched the phase III trials, the final study required before gaining authorisation, for the experimental shot in December in Uzbekistan, and kicked off testing in Pakistan in February.
The vaccine is also being tested in Ecuador and Indonesia. China approved the vaccine for emergency use on March 10 and it's now among several being administered across the nation.
The vaccine uses a similar technology as Novavax Inc's shot, which boasts a 90 per cent efficacy against symptomatic Covid but has appeared to be far less effective in an earlier study against the Beta variant. The Novovax is a protein-based coronavirus vaccine.
In comparison, the mRNA vaccines from Pfizer Inc and Moderna have largely held up well against variants, including the Delta strain that was first found in India and has spread to more than 100 countries around the world.