The second shot of Nanocovax, a Vietnamese Covid-19 vaccine, has proven safe and immunogenic, the Vietnam Military Medical University said after volunteers were vaccinated starting Thursday.
The second shot produces an immune response four to five times higher than the first, it said.
Ho Anh Son, deputy director of the university’s Institute of Biomedicine and Pharmacy, said researchers would need to monitor volunteers’ health from the next six months to a year to ascertain the stability and longevity of antibodies produced.
Data relating to the vaccine trials are being processed to be sent to the Ministry of Health.
The second phase of the trials could commence immediately after the Lunar New Year in mid-February with 560 volunteers, Son said.
On Thursday morning a second shot of the 25 mcg dose was given to three volunteers aged 25-42, who had their first on December 17.
Ten others got the 75 mcg shot, and they are being monitored.
Nanocovax, produced by the Nanogen Pharmaceutical Biotechnology JSC, was Vietnam’s first coronavirus vaccine to enter human trials.
Sixty volunteers participated in the first phase in which they were split into three groups to be given 25 mcg, 50 mcg and 75 mcg doses.
Each will get two doses 28 days apart.
All members of the 25 mcg and 50 mcg groups have had their first shots, with three from the former also getting the second.
Thirteen people in the 75 mcg group have got the first shot and the rest are expected to get theirs on Friday.
Vietnam has three other vaccines under development by the Institute of Vaccines and Medical Biologicals, the Vaccine and Biological Production Company No. 1 and the Center for Research and Production of Vaccines and Biologicals.
The country has had 1,531 Covid-19 cases so far and 35 deaths.
No community transmission has been recorded for over a month.