People in good health who have already had three Covid-19 boosters may not benefit from administering any more as they appear unlikely to guard against new strains of the virus, according to a local medical expert who cited the results of a recent US study.
`This is because existing Covid-19 vaccines are based on the Wuhan strain of the coronavirus, whereas the dominant new strains have mutated greatly, said Dr Thiravat Hemachudha, chief of the Thai Red Cross's Emerging Infectious Diseases Health Science Centre.
