Experts say an individual requires multiple doses of a COVID vaccine due to mutations and constant change in the variants of the novel coronavirus.
Speaking during a media briefing in Colombo, Consultant Physician Dr. Sarath Gamini De Silva noted that there is a risk of recurrence of viruses such as COVID.
He said the majority of the vaccines for viruses, especially those administered to children, will provide cover for years and therefore adults are not generally inoculated.
Dr. Sarath Gamini De Silva said however an individual can be infected by the coronavirus on multiple occasions since new variants are continuing to emerge.
He said therefore several doses of a vaccine may be required until experts have complete understanding of the novel coronavirus.
Dr. Sarath Gamini De Silva noted that scientists are still studying the virus and its mutations and therefore they will not be able to make definitive projections of how it will behave in about two years.
He also said they are unaware whether the antibodies generated through vaccines will remain in an individual after a couple of years.