KOMPAS.com - China's top disease control official says the country is formally considering mixing Covid-19 vaccines as a way of further boosting vaccine efficacy.
Available data shows Chinese vaccines lag behind others including Pfizer and Moderna in terms of efficacy, but require less stringent temperature controls during storage.
Gao Fu, the director of the Chinese Center for Disease Control and Prevention, said on Saturday that giving people doses of different vaccines is one way to improve vaccines that, "don't have very high rates of protection."
"Inoculation using vaccines of different technical lines is being considered."
He did not specify if he was referring to foreign or domestic vaccines.
Gao said that taking steps to "optimize" the vaccine process including changing the number of doses and the length of time between doses was a "definite" solution to efficacy issues.
Two injections of a vaccine developed by China's Sinovac Biotech, when given less than three weeks apart, was 49.1 percent effective based on data from a phase 3 trial in Brazil.
This was below the 50 percent threshold set by World Health Organization (WHO), according to a paper published by Brazilian researchers on Sunday ahead of peer review.
But data from a small subgroup showed the efficacy rate increased to 62.3 percent when the doses were given at intervals of three weeks and longer.
The overall efficacy rate for the vaccine was slightly above 50 percent in the trial.
China has developed four domestic vaccines approved for public use and a fifth for smaller-scale emergency use.
An official said on Saturday the country will likely produce three billion doses by the end of the year.
No detailed efficacy data has been released on vaccines made by China's Sinopharm.
It has said two vaccines developed by its units are 79.4 percent and 72.5 percent effective, based on interim results.
Both vaccine makers have presented data on their Covid-19 vaccines indicating levels of efficacy in line with those required by WHO.
China has shipped millions of its vaccines abroad and officials and state media have fiercely defended the shots while calling into question the safety and logistics capabilities of other vaccines.
Gao also rejected claims by some media reports that said Chinese Covid-19 vaccines have a low protection rate, telling Global Times that it was "a complete misunderstanding."