China’s inactivated Covid-19 vaccine entered the second phase of the clinical trial on Friday, Xinhua reports. An inactivated vaccine, sometimes called a killed vaccine, uses virus particles that have deteriorated and lost their ability to cause disease.

The vaccine is being developed by Wuhan Institute of Biological Products under the China National Pharmaceutical Group (Sinopharm) and the Wuhan Institute of Virology under the Chinese Academy of Sciences. Clinical trials began on 12 April. 

In a statement, Sinopharm said that 96 patients, in three age groups, were given the vaccine on Thursday, April 23. The vaccine has not shown any side effects so far and volunteers taking part are still under observation. The second phase of the clinical trial will focus on the vaccination procedure. The trial process is expected to last around a year.

China has approved three Covid-19 vaccine candidates for clinical trials – including an adenovirus vector vaccine prototype that has entered the second phase of the clinical trial.