Medical workers carry out nucleic acid tests in Hangzhou in April. (PHOTO: VCG)

By ZHANG Jiaxing & QI Liming

The vaccine designed exclusively to combat the Omicron variant by China National Biotech Group began its clinical trails in May. The research of a special vaccine against Omicron variant is underway.

Shortly after Omicron variant emerged in December 2021, WHO had already warned that preliminary evidence suggested it could make COVID-19 vaccines less effective and put people at a higher risk of reinfection. This warning has since been confirmed as Omicron has become the dominant strain of the virus.

When neutralizing antibodies produced by the prototype strain significantly decreased its neutralizing activity against Omicron, a new vaccine was needed. The results of the current study showed that neutralizing activity of the neutralizing antibody was indeed significantly decreased in response to Omicron.

During the development of the vaccine, the research team paid close attention to cellular immunity. They included continuous testing of cellular immunity in the design of the clinical study. Cellular immunity will compensate for the generally poor persistence of neutralizing antibodies in the novel coronavirus.

According to the current situation of COVID-19 vaccination in China, clinical research programs will be carried out in two ways.

One way is that clinical trials of one and two doses of Omicron vaccine will be given to those who have received two or three doses of inactivated COVID-19 vaccine.

The other way is that the Omicron vaccine will be administered directly to unvaccinated people to observe its safety and immunogenicity. If data is obtained from clinical study, the new vaccine can be administered directly to the unvaccinated population.

The researchers say clinical trials of the new vaccine were not designed as a fourth dose of the vaccine, but rather a study of vaccination based on whether full immunity had been completed.