China's medical products regulator said on Thursday that it had approved two more COVID-19 vaccines for public use, raising the number of domestically produced vaccines that can be used in China to four.
The two newly cleared vaccines are made by CanSino Biologics Inc (CanSinoBIO) and Wuhan Institute of Biological Products, an affiliate of China National Pharmaceutical Group (Sinopharm).
They join a vaccine from Sinovac Biotech approved earlier this month, and another from Sinopharm's Beijing unit approved last year.
Prior to formal approval for wider public use by the National Medical Products Administration, millions of doses of the two Sinopharm vaccines and Sinovac shot had been administered in China's vaccination program. The program targets select groups of people facing a higher risk of infection.
CanSinoBIO's vaccine has been given the green light for use by military personnel.
So far, China has not approved COVID-19 vaccines developed by Western drug makers.
The four approved Chinese vaccines can be stored at normal freezer temperatures - a potential selling point in less affluent countries that might have difficulty deploying vaccines from Pfizer and Moderna that require much colder temperatures for longer-term storage.
The three companies have all secured supply deals overseas, and China has donated doses made by Sinopharm's Beijing unit to numerous countries. China is exporting vaccines to 27 countries and providing free doses to 53 countries, a foreign ministry spokesman said on Tuesday.
Interim results from large late-stage trials showed the vaccine from Sinopharm's Wuhan unit was 71.25% effective against the disease caused by the new coronavirus, lower than the 79.34% efficacy reading of the shot from its Beijing unit using similar technology, according to company statements.
Sinovac said a Brazil-based Phase III clinical trial showed its vaccine was 50.65% effective against COVID-19, while a human test in Turkey yielded a 91.25% efficacy rate, based on preliminary results.
CanSinoBIO said its vaccine was 68.83% effective at preventing symptomatic COVID-19 disease two weeks after a single-dose vaccination, citing interim data, while the rate fell to 65.28% four weeks after one shot.
Detailed data interpreting these headline figures are yet to be made available to the public.