The Gavi vaccine alliance is in talks with Chinese drugmaker Sinovac Biotech to expand the COVAX dose-sharing portfolio available to poor countries following the World Health Organization (WHO)'s approval of its COVID-19 vaccine on Tuesday, a Gavi spokesperson said.

"Gavi, on behalf of the COVAX Facility, is in dialogue with several manufacturers, including Sinovac, to expand and diversify the portfolio further and secure access to additional doses for facility participants," she said on Wednesday.

Sinovac's COVID-19 vaccine is the second Chinese vaccine to gain emergency use approval from the WHO, after Sinopharm was given the global body's official support on May 7.

It means that two of the eight vaccines on the international vaccine program COVAX have been produced and developed in China. The primary aim of the program, overseen by the WHO, Coalition for Epidemic Preparedness Innovations and the Gavi alliance, is to provide doses for at least 20 percent of all nations' populations.

(With input from Reuters)