The Expert Committee on COVID-19 Vaccination (EC19V) in Singapore recommends that the healthcare and frontline workers; people and staff in institutionalised settings; and people aged 30 years and above should receive a booster dose of a PSAR mRNA vaccine from six months after the completion of the two-dose primary vaccination. Both the Pfizer-BioNTech and the Moderna COVID-19 vaccines are mRNA-based.

While two doses of the vaccine provide excellent protection against severe disease, the experts have evidence that there is waning protection against infection over time.

Locally, an increased risk of vaccine-breakthrough infections has been observed, starting from around six months after the completion of the first two vaccine doses. This is contributing to the high daily rates of new COVID-19 infections in the country, although protection against severe disease remains high. Booster vaccination is therefore needed to reduce COVID-19 infection and transmission.

There is now good international data that a booster dose of the vaccine is safe, enhances protection against COVID-19 infection and ensures continued excellent protection against severe disease.

The risk of myocarditis/pericarditis with the first two doses of the mRNA vaccines is extremely rare but has a higher incidence among adolescents and younger adults.