Last week, Brazil’s most populous state São Paulo signed a $90 million deal with Chinese vaccine maker Sinovac to receive 46 million doses of CoronaVac, the company’s leading vaccine candidate. Sinovac has been testing CoronaVac in Phase III trials in Brazil since July, and is also engaged in similar late-stage trials in Indonesia and Turkey.

“São Paulo will be one of the first places in the world to vaccinate the public,” São Paulo Gov. João Doria said at a press conference on Wednesday, adding that his government had already obtained 6 million CoronaVac doses for potential distribution. Brazil has recorded nearly 5 million cases of coronavirus, the third most in the world behind India and the U.S. São Paulo is Brazil’s hardest-hit region, recording over 1 million of those cases, more than double the total of any other Brazilian state.

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On Friday, Doria asked Brazil’s health regulator Anvisa to register Sinovac’s candidate for potential use, a major step in the country’s vaccine-approval process. Anvisa later confirmed that it had received data related to Sinovac’s candidate. Brazil’s Butantan Institute, a research center running Sinovac’s trials, said in a statement that CoronaVac’s approval in Brazil will require the results of the candidate’s Phase III trials. Sinovac’s Latin America head Xing Han said Brazil’s Phase III trials should be finished by the start of December, putting possible distribution of CoronaVac in São Paulo on one of the fastest timelines for a COVID-19 vaccine.

Chinese state-run vaccine maker Sinopharm said in August that its vaccine may be ready in China by December, but Sinovac’s potential December distribution in Brazil puts it ahead of some of its other global competitors.

Stéphane Bancel, CEO of U.S. vaccine maker Moderna, said last week that Moderna is aiming to receive approval and distribute its vaccine in the spring of 2021. The Times of London reported last week that AstraZeneca and Oxford University’s vaccine effort may be ready for distribution by the start of 2021 in the U.K.

The leader in the race, at least based on projected timelines, is Pfizer. CEO Albert Bourla said in September that Pfizer’s vaccine, which is being produced in partnership with Germany’s BioNtech and China’s Fosun Pharma, may be ready for limited distribution as early as next month.

Unlike its foreign counterparts, Sinovac is also already distributing its vaccine on a limited basis in China.

Sinovac is one of three Chinese vaccine makers involved in China’s controversial emergency use program, and says it has granted tens of thousands of doses to Beijing’s government to distribute among city employees.

Sinovac has meanwhile ramped up production of CoronaVac with its sights set on serving markets abroad.

In August, Sinovac announced that a new production plant in Beijing could produce 300 million doses annually. In September, Sinovac CEO Yin Weidong said that because of China’s relative success in containing COVID-19, his company hopes to sell CoronaVac primarily to other countries. (To be clear, China’s low coronavirus case numbers do not eliminate its need for a vaccine.)

“At the very beginning, our strategy was designed for China and for Wuhan,” Yin told reporters in September. “Soon after that in June and July we adjusted our strategy, that is to face the world.”

More must-read international coverage from Fortune:

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• There’s an ulterior motive to China’s carbon neutral pledge: Cornering the green tech market
• The pandemic’s “new poor”: Poverty in parts of Asia could rise for the first time in 20 years
• One major Asian economy besides China is set for growth this year—and its GDP just rose 2.6%
• China’s most popular holiday travel destination is in Wuhan, the onetime COVID epicenter