BEIJING, June 17 (Xinhua) -- China has unveiled the results of the phase 1 and phase 2 clinical trials of an inactivated COVID-19 vaccine candidate, which shows promising results in both safety and efficacy, according to the China National Pharmaceutical Group (Sinopharm).

The vaccine, developed by the Wuhan Institute of Biological Products under the China National Biotec Group (CNBG) affiliated to Sinopharm, involved 1,120 volunteers aged between 18 and 59 in its clinical trials, which started on April 12.

The results revealed a good safety record, with no cases of severe adverse effects found in the clinical trials. The vaccine receivers inoculated with two injections in different procedures and doses have all produced high titers of antibodies.

For those receiving two middle-dose injections at intervals of 14 days and 21 days, the seroconversion rate of neutralizing antibodies reached 97.6 percent. For those receiving two middle-dose injections at an interval of 28 days, the seroconversion rate of neutralizing antibodies reached 100 percent.

The CNBG is actively promoting overseas cooperation in the phase 3 clinical trial of the vaccine and has secured the intention of cooperation of several companies and research institutions from other countries.

The company has also built a production workshop with high-level biosafety, which could help ensure the supply of vaccines for emergency use.