The Expert Committee on COVID-19 Vaccination (EC19V) in Singapore has been closely reviewing the data regarding the need for additional vaccine doses and recommends the following:

Persons who are moderate to severelu immunocompromised should receive a third dose of the same Pandemic Special Access Route (PSAR) mRNA vaccine two months after their second dose as part of their primary course of vaccination, and,

Persons aged 60 years and above, as well as residents of aged care facilities should receive a booster dose of a PSAR mRNA vaccine six to nine months after the completion of vaccination with two doses.

There is evidence that people who are moderate to severely immunocompromised have a blunted immune response to the two-dose COVID-19 vaccination. Studies have shown that a third dose increases the likelihood that immunocompromised persons develop a robust protective immune response.

While COVID-19 vaccination continues to provide a high level of protection against severe disease from infection, there is data that protection against asymptomatic and symptomatic infection can wane over time from the initial vaccination.

The current strong protection against severe disease could decrease in the months ahead particularly for those who are at higher risk.  A booster dose will increase the level of immunity and ensure that a high level of protection from severe disease is maintained across a longer period.