In a small study, a Chinese mRNA vaccine candidate exhibited a steep decline in neutralizing antibody activity against the Omicron variant; however, a booster induced antibody production in animal experiments, noted researchers.

The ARCoV vaccine has been developed by the Academy of Military Medical Sciences (AMMS), Suzhou Abogen Biosciences and Walvax Biotechnology (300142.SZ), and is currently under an international Phase III clinical trial. In a lab study that assessed samples from 11 vaccinated individuals, eight had low but detectable neutralizing activity against Omicron, reported researchers in a letter to editors published in Cell Research. The neutralizing antibody level against Omicron was 47 times lower compared to the level against a wild-type virus with no major mutations.

In animal tests, a third dose administered around nine months following the second jab could induce the production of neutralizing antibodies against the Omicron variant and a wild-type strain… (Reuters, February 16, 2022)