Indonesia has approved a COVID-19 vaccine produced by Chinese company Anhui Zhifei Longcom Biopharmaceutical for emergency use, the country's food and drug agency BPOM said on Thursday.

"Today, BPOM again announces that we have approved a COVID-19 vaccine product under the trade name Zifivax, which was developed with a recombinant protein sub-unit platform," BPOM's head Penny Lukito told a virtual press conference.

The vaccine has an overall efficacy rate of about 81 percent, and its efficacy against the more transmissible Delta variant is 77.47 percent, Lukito said, citing the results of the Phase-3 clinical trials of the vaccine involving 28,000 people in China, Uzbekistan, Pakistan, Ecuador and Indonesia.

In Indonesia, around 4,000 people aged between 18 and 59 years old were involved in the trials. 

The vaccine is also more effective against other variants of the novel coronavirus, namely Alfa (92.93 percent), Gamma (100 percent), and Kappa (90.0 percent), the results showed. 

Zifivax is the fourth Chinese vaccine cleared for use in Indonesia after the Sinovac, Sinopharm and CanSino vaccines.

Once Asia's COVID-19 epicenter, Indonesia has vaccinated a fifth of its population of about 270 million people.

It has recorded more than 4.2 million coronavirus cases and 142,000 deaths overall, but average daily infections have fallen dramatically since the peak of its crisis in July.

(With input from agencies)