COVID-19 Booster Vaccination in Malaysia

After battling the extreme acute respiratory syndrome-causing coronavirus disease 2019 (COVID-19) pandemic for more than two years, the vaccines have enabled the transition to endemicity. Despite vaccine advancement, Mankind will be one step behind viruses like SARS-CoV-2 as the latter continuously evolve into variants with higher transmissibility. They demonstrate immune escape through genetic mutation or viral recombination which occurs during replication of the genome. Vaccine variants in the form of booster doses are required following the initial vaccination series to prevent the spread of the more dangerous SARS-CoV-2 variants of concern (VoC) such as Omicron. Protection against COVID-19 for those with chronic comorbid conditions, those who are immunosuppressed, and vulnerable, at-risk population was postulated to decline rapidly with time from their last vaccination. As the elicited adaptive immune response declines, older adults and at-risk populations continue to be at the highest risk of morbidity and mortality from future VoC. Current vaccines are effective at reducing severe respiratory-related illnesses, hospitalisation, and mortality attributed to COVID-19, yet cannot fully protect against developing an infection. The article summarises the evidence and policy recommendations for COVID-19 booster shots. This information is useful for future planning by policymakers and healthcare providers to make vaccination policies and decisions, particularly for including the COVID-19 vaccines in national immunization programs.