Two more homegrown COVID-19 vaccines are being reviewed by China's top drug regulator to obtain conditional market approval, the drugmakers announced on Feb 24.

CanSino Biologics, a company based in Tianjin municipality, said it had filed for conditional authorization to the National Medical Products Administration on Sunday for its one-shot vaccine, jointly developed with a research team under the Academy of Military Sciences.

With a single injection, the candidate has an efficacy rate of 65.28 percent at preventing all symptomatic cases and a rate of 90.07 percent at preventing severe infections 28 days after inoculation, the company said in a statement released on Wednesday.

The data is based on interim results from Phase-3 clinical trials enrolling more than 4,000 participants in Pakistan, Mexico, Russia, Chile and Argentina, according to the statement.

On the same day, the Wuhan Institute of Biological Products, administered by State-owned Sinopharm, said it also applied for conditional market approval to the top drug regulator on Sunday.

Interim results from late-stage human trials show its inactivated vaccine has an overall efficacy rate of 72.51 percent, according to the company. Full inoculation with this vaccine requires two doses.

China has so far granted conditional approval to two vaccines, one manufactured by Sinopharm's Beijing Institute of Biological Products and the other from Beijing-based Sinovac Biotech.

Wu Yuanbing, an official with the Ministry of Science and Technology, said in late January that a total of 16 homegrown COVID-19 vaccines have entered clinical trials.