On Monday, the Chinese biotech firm CanSino Biologics said in a statement to the Hong Kong stock exchange that China’s Central Military Commission gave the go-ahead for China’s military to inject soldiers with Ad5-nCoV, the company’s leading vaccine candidate, for a period of one year.

In the statement, CanSino Biologics chairman Yu Xuefeng said the vaccine candidate’s Phase I and II clinical trials demonstrated a “good safety profile” and high levels of immune response in patients. But he cautioned that the trials only show that the vaccine has the potential to prevent COVID-19 and that the military’s approval of the vaccine does not guarantee it will be authorized for broader commercial use in future.

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CanSino Biologics has been developing the vaccine in conjunction with the Academy of Military Medical Sciences, a medical research institute run by the People’s Liberation Army. The two organizations are basing the experimental COVID-19 vaccine on their previous collaboration on an Ebola vaccine. The Chinese government approved the Ebola vaccine for widespread use in 2017.

CanSino’s Ad5-nCoV candidate has long been China’s leading COVID-19 vaccine candidate, after it became the first in the world to begin clinical trials on March 16. The company conducted Phase I and II trials in Wuhan, China, and published the results of the trials in The Lancet medical journal.

In mid-May, CanSino also announced a partnership with the National Research Council of Canada and got the green light to begin clinical trials with Canadian patients. The trials are being conducted over a six-month period in partnership with researchers at Dalhousie University in Halifax, Nova Scotia.

Two other China-based COVID-19 vaccine projects—one developed by state-owned Wuhan Institute of Biological Products and the other by Beijing-based biotech firm Sinovac—entered human testing earlier this year, making them some of the world’s most promising candidates.

As of Sunday, the World Health Organization said 17 COVID-19 candidate vaccines were in clinical evaluation, with another 131 in preclinical stages. The global scientific community is working at an unprecedented speed to develop an inoculation against COVID-19, which has infected more than 10 million people and killed more than 500,000 globally in the worst public health crisis in a century.

Yu founded CanSino Biologics in 2009, and its investors include Chinese venture capital firms such as Qiming Venture Partners and Lilly Asia Investors.

CanSino Biologics’ stock traded 5% higher on the Hong Kong stock exchange on Monday morning before returning to its Friday closing price by Monday afternoon. The company’s market capitalization has more than tripled to $5.3 billion since the start of the coronavirus pandemic. On Jan. 2, 2020, the company’s share price was HKD 59, and on Monday it closed at HKD 219.