BRASILIA, Jan. 22 (Xinhua) -- Brazil's Health Regulatory Agency (Anvisa) unanimously approved on Friday the emergency use of another 4.8 million doses of the CoronaVac vaccine against COVID-19.

The request was made by the Sao Paulo-based Butantan Institute on Monday, a day after Anvisa authorized the use of the first batch of 6 million doses of CoronaVac, which kicked off a countrywide COVID-19 vaccination process.

The vaccines were developed by Chinese pharmaceutical firm Sinovac Biotech in partnership with the Butantan Institute.

Anvisa said it considers CoronaVac a "safe, quality and effective vaccine," noting that its application in the first week of immunization has not presented any problems.

Although Anvisa authorized the emergency use of the Sinovac and the Oxford University/AstraZeneca vaccines against COVID-19 on Sunday, only CoronaVac doses were available in the South American country until Friday.

All Brazilian states and the Federal District have started the vaccination process, with priority given to health professionals, indigenous people and seniors living in nursing homes.

The South American country has logged 8,753,920 COVID-19 cases and 215,243 deaths as of Friday, according to the latest data from its health ministry.