China’s COVID-19 vaccine trial, the first such vaccine to reach phase 1 clinical trial, has been found to be safe, well-tolerated, and able to generate an immune response against SARS-COV-2 in humans, according to a study published online on Friday by medical journal The Lancet.

China has approved three COVID-19 vaccine candidates for clinical trials, with the recombinant adenovirus vector-based vaccine (Ad5-nCoV) listed as the world’s first vaccine to go into phase two by the World Health Organization. This type of vaccine is able to act as a natural infection and is especially good at teaching the immune system how to fight the virus.

(With inputs from Xinhua.)