AstraZeneca (AZN -0.25%) has filled a notable gap in its coronavirus vaccine production plans. On Thursday, the sprawling pharmaceutical company announced in a social media post that it had made a deal to have BioKangtai Biologics produce a minimum of 100 million doses of its AZD1222 vaccine candidate in China for that country's immense market.

Guangdong-based BioKangtai has been granted exclusive rights to develop, produce, and market the vaccine in China. AstraZeneca did not disclose the financial terms of the arrangement, but it did say the collaboration might not remain limited by that country's borders. "In the future, the two parties will continue to explore the possibility of cooperation in other regions and markets," it wrote.

A young girl in a face mask receiving a shot from a medical professional.

Image source: Getty Images.

AZD1222 is one of the leading coronavirus vaccine candidates; a phase 1/2 clinical trial of it showed that, after one month, it produced the type of neutralizing antibodies that can keep the coronavirus at bay in nearly all of the 35 participants inoculated.

AstraZeneca is developing AZD1222 in collaboration with the U.K.'s University of Oxford. The company has now covered most global markets with production deals, but those, of course, will kick in only if the  candidate performs well enough in late-stage clinical testing and is subsequently approved by regulators. AstraZeneca and Oxford began a 2/3 phase clinical trial of it in May.

Anticipating that levels of demand for an effective COVID-19 vaccine are likely to be unprecedented, the company has ambitions to produce 2 billion doses of AZD1222 by the end of next year. It has already pledged to supply 300 million doses to the U.S. market and 300 million to the countries of the European Union, among other promises.

Shares of AstraZeneca fell 1.4% on Friday, in contrast to the S&P 500 index, which closed with a gain of less than 0.1%.