SAO PAULO, Brazil (AFP) — The manufacturers of two COVID-19 vaccines developed by Chinese pharmaceutical firm Sinovac and Oxford-AstraZeneca filed the first applications Friday for regulatory approval in hard-hit Brazil, officials said.

Federal health regulator Anvisa now has 10 days to respond to the applications, though it said that could include asking the sponsors for more information.

One application was submitted by the Butantan Institute, a public health centre in Sao Paulo that is working with Sinovac to test and produce its CoronaVac vaccine.

The other was from the Fiocruz Foundation, which is based in Rio de Janeiro and is working with the University of Oxford and its partner, the British-Swedish pharmaceutical firm AstraZeneca, in a similar partnership.

The applications came a day after officials announced CoronaVac had shown effectiveness of 78 per cent in clinical trials in Brazil, news that Sao Paulo Governor Joao Doria called “historic”.

Sinovac has not yet released worldwide results from the final stage of clinical trials, which are also being carried out in Chile, Indonesia and Turkey.

As for the Oxford vaccine, results published in December found it was 62 per cent effective for volunteers given two full doses and 90 per cent effective for those given a half dose followed by a full dose.

But both vaccines appear to be short of the more than 90 per cent effectiveness reported for the vaccines from US pharmaceutical firms Pfizer and Moderna.

The CoronaVac and Oxford vaccines have been caught up in a political battle in Brazil between Doria and far-right President Jair Bolsonaro, likely opponents in presidential elections next year.

The federal government initially passed on CoronaVac, which Bolsonaro has derided as “Joao Doria’s Chinese vaccine”.

But after struggling to secure enough doses for Brazil’s population of 212 million, the health ministry announced Thursday it had signed a deal with the Butantan Institute for 100 million doses of the vaccine for use nationwide.

Fiocruz for its part plans to import two million doses of the AstraZeneca jab produced by India’s Serum Institute, the world’s largest manufacturer of vaccines by volume.

On Friday, Bolsonaro sent a letter to Indian Prime Minister Narendra Modi in which “he urgently requested the supply of the two million doses” of the AstraZeneca jab.

The early delivery would allow the immediate implementation of the vaccination program, Bolsonaro said.

Brazil has the second-highest death toll in the pandemic after the United States, with more than 200,000 people killed by COVID-19.

The government has yet to set a start date for its vaccination campaign, a delay that has drawn scathing criticism from Bolsonaro opponents.