KUALA LUMPUR: The Health Ministry is studying the need for a possible fourth Covid-19 vaccine dose for people who have taken their first two doses of the Sinovac (CoronaVac) vaccine, followed by a Pfizer-BioNTech (Comirnaty) booster shot.
Health Minister Khairy Jamaluddin said the ministry's technical committee is looking into the matter to ensure recipients achieve the protective levels needed against the more transmissible Omicron variant.
He was commenting on a recent study which found that Sinovac's two-dose Covid-19 vaccine followed by a Pfizer-BioNTech booster shot showed a lower immune response against the Omicron variant compared with other strains.
"We are aware of the study. Our technical committee is currently reviewing the information and they will make the necessary recommendations to the Covid-19 Immunisation Task Force (CITF) on whether those who received Sinovac as their primary vaccine and a Pfizer booster would require another dose.
"It is too early for us to come to a conclusion now," he said during a press conference here today.
Reuters, on Friday, reported that the study, which has not been peer-reviewed yet, was conducted by researchers from Yale University, the Dominican Republic's Ministry of Health and other institutions.
According to the study, the Sinovac two-dose regimen along with the Pfizer shot produced an antibody response similar to a two-dose mRNA vaccine.
Antibody levels against Omicron were 6.3-fold lower when compared with the ancestral variant and 2.7-fold lower when compared with Delta, it said.
Professor Akiko Iwasaki, who is one of the authors of the study, on Dec 30 tweeted that CoronaVac recipients may need two additional booster doses to achieve protective levels needed against Omicron.