Half an mRNA dose can boost immunity for those who got Sinovac jabs: virologist
A half dose of an mRNA Covid-19 vaccine is enough as a booster for those who have received inactivated vaccines earlier, a top virologist said.
In a Facebook post on Friday, Dr Yong Poovorawan said that his study shows that either a full or half dose of the Pfizer or Moderna vaccine provided high immunity to those whose first two shots were the inactivated vaccine Sinovac.
He added that it was globally accepted that only half a dose or 50 micrograms of the Moderna vaccine provides enough immunity. Yong is a professor of paediatrics at Chulalongkorn University’s Faculty of Medicine.
He confirmed that any booster, be it AstraZeneca, an mRNA vaccine or Covovax, will provide high immunity against the virus.
However, he said, people’s immunity drops some four months after receiving a booster shot.
Yong said his study, “Comparison of the reactogenicity and immunogenicity of a reduced and standard booster dose of the mRNA COVID-19 vaccine in healthy adults after two doses of inactivated vaccine”, was published on the medRxiv website on August 22. The study has yet to be peer-reviewed.
