BEIJING (REUTERS) - Chinese researchers have started a second phase human trial of a possible coronavirus vaccine, the Institute of Medical Biology at Chinese Academy of Medical Sciences (IMBCAMS) said on Sunday (June 21), in efforts to further assess effectiveness and safety.

IMBCAMS began on Saturday a phase two human test for its experimental shot, which is among six possible vaccines Chinese scientists are testing in humans, following an on-going phase one study that has recruited about 200 participants since May, the institute said on Sunday in its social media channel.

The phase two trial will determine the shot's dose and continue to evaluate whether the potential vaccine can safely trigger immune responses in healthy people.

About a dozen vaccines are in different stages of human tests globally, as the World Health Organisation warns the coronavirus pandemic is accelerating and "the world is in a new and dangerous phase".

However, none of the vaccine trials have passed large-scale, late-stage phase three clinical trials, a necessary step before getting regulatory approval for sale.

IMBCAMS said it expects to use a plant dedicated to producing a coronavirus vaccine this year to prepare for China's future vaccine supplies.

As early as by the end of 2020, certain groups of people with special needs can use experimental vaccines under urgent circumstances, Dr Gao Fu, director at the Chinese Centre for Disease Control and Prevention, said last month.

The coronavirus, which was first detected in China late in 2019, has infected 8.81 million people globally and killed more than 460,000 people.