HKU study: Kexing’s protection still inadequate after two doses.
Chinese biotech company Kexing claims that the third “booster” dose of its new crown vaccine is 94 percent effective against the omicron variant, but a University of Hong Kong study shows that after two doses, Kexing’s protection is still clearly inadequate.
The Nikkei Asian Review reports that the study, led by Yuen Kwok-yung, chair professor of microbiology at HKU, found that none of the 25 people who received the Coxin vaccine produced sufficient levels of serum antibodies. Serum antibodies are an indicator that provides a rough estimate of whether a person is immune.
The report quoted To Kai-hong, a clinical associate professor in the Department of Microbiology at the University of Hong Kong and a member of the research team, as noting, “We think this means that the vaccine will be less effective against the Omicron variant.”
The study also looked at 25 people who had received two doses of either the Pfizer or Fibrate vaccine. The researchers found that five people were neutralized against the Omicron variant.
According to the World Health Organization, as of Tuesday, the Omicron variant coronavirus strain had spread to 77 countries. The emergence of the Omicron variant has prompted some governments to regulate travel and other activities because countries are concerned that it is more transmissible than earlier variants, even the highly infectious Delta variant.
In pushing back against questions about its vaccine, Cushing said its own laboratory studies showed that seven of 20 people who received two doses of Cushing’s vaccine tested positive for neutralizing antibodies, meaning its effectiveness rate was 35 percent. Of the 48 people who received three doses, 45, or 94 percent, tested positive for antibodies.
Coxing claims, “These results indicate that the third dose of Coxing vaccine is effective in improving seronegativity against the Omicron virus strain.”
Coxing’s study was based on two samples of Omicron virus obtained from Hong Kong. The company said it is conducting further studies involving serum samples with different antibody levels to fully evaluate the efficacy of Coxin against Omicron.
Kexing is one of two Chinese vaccines approved by the WHO for emergency use, out of a total of eight worldwide. WHO said Wednesday that preliminary evidence suggests the existing New Crown Pneumonia vaccine may be less effective against Omicron, but added that more data are needed to understand the details.
Another study announced Sunday by scientists from the University of Hong Kong and the Chinese University of Hong Kong showed that fubatide was 32 times weaker at neutralizing variants than it was at neutralizing the original strain of virus that causes neo-coronavirus.