SAO PAULO: Brazil has gathered enough infection data from a late-stage trial of an experimental COVID-19 vaccine developed by China's Sinovac Biotech and expects to have interim results on its efficiency in early December, trial organizers said on Monday.

Dimas Covas, director of Butantan biomedical research institute that is running the late-stage trial of the Sinovac vaccine in Brazil, said it now has 74 confirmed cases among its trial participants, above the 61 initial milestone set for interim efficiency analysis.

He said an independent committee is likely to release the efficiency results in the first week of December based on its analysis of the data.

The news comes as Britain's AstraZeneca Plc on Monday joined its U.S. rivals Pfizer and Moderna and Russia in announcing positive results in pivotal trials, raising hopes that the world would soon have successful vaccines to end the pandemic.

Covas said Brazil's health ministry now has all the information needed to include Coronavac in the national program, while São Paulo Health Secretary Jean Gorinchteyn expected on Monday Brazil's regulator to approve the use of the Sinovac vaccine, CoronaVac, by January.

João Gabbardo, head of the Sao Paulo's COVID-19 contingency committee, said at the same event that he expects China's health regulator to approve Sinovac's CoronaVac in December, which could hasten approval in Brazil.

The Sinovac vaccine has been promoted by Sao Paulo Governor João Doria, a move which has put him at odds with President Jair Bolsonaro who is a vocal China skeptic.

Bolsonaro has attacked the Chinese vaccine for lacking credibility and it remains unclear whether the federal government will include it in its national inoculation program.

The ministry said on Sunday it planned to sign non-binding letters of intent to buy vaccines from Pfizer Inc, India's Bharat Biotech, the Russian Direct Investment Fund, Moderna Inc and Janssen, a unit of Johnson & Johnson , but made no mention of Sinovac's candidate.