China's Sinovac Biotech has secured $515 million in funding from a domestic firm to double production capacity of its coronavirus vaccine, the companies said on Monday, as it expects efficacy data of its experimental shots this month.

The investment comes as Sinovac expands supply deals and trials of its experimental COVID-19 vaccine CoronaVac with more countries following positive results from early- to mid-stage clinical trials.

China's Sino Biopharmaceutical Limited said on Monday a business unit will invest $515 million in Sinovac Life Sciences, a subsidiary of Sinovac, to help development and production of CoronaVac.

Sinovac said in a separate statement that it would be able to manufacture 300 million vaccine doses annually and aims to complete construction of a second production facility by the end of 2020 to increase annual COVID-19 vaccine production capacity to 600 million doses.

CoronaVac is one of three experimental COVID-19 vaccines China has been using to inoculate around 1 million people under an emergency use program.

The company has also secured CoronaVac supply deals with several countries including Indonesia, Turkey, Brazil and Chile, and is holding talks with the Philippines for potential sale.

Indonesia received its first shipment of a COVID-19 vaccine from China on Sunday. President Joko Widodo said in an online briefing that the country received 1.2 million doses of a vaccine that it has been testing since August from China's Sinovac Biotech Ltd.

He added that the government plans to receive another 1.8 million doses in early January.

Late-stage trials of the Sinovac vaccine are also under way in Brazil and Turkey.

Brazil's Butantan Institute biomedical center, which is running a Phase 3 trial of CoronaVac in the country, said last week that Sinovac was expected to publish efficacy results from its vaccine trials by December 15.

Turkish Health Minister Fahrettin Koca earlier announced that the country had signed a contract to buy 50 million doses of the COVID-19 vaccine from Sinovac Biotech. 

He said at least 10 million doses of the vaccine will be delivered in December, but the target is to get about 20 million doses. Another 20 million doses are scheduled for January 2021.

(With input from Reuters)