The Expert Committee on COVID-19 Vaccination (EC19V) further recommends that the following persons should receive a booster dose of a PSAR mRNA vaccine from six months after the completion of the two-dose primary vaccination (refer to Annex):
a. Healthcare and frontline workers
b. Persons and staff in institutionalised settings
c. Persons aged 30 years and above
Booster Vaccination Enhances Protection
2. While two doses of the vaccine provide excellent protection against severe disease, we 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 locally, although protection against severe disease remains high. Booster vaccination is therefore needed to reduce COVID-19 infection and transmission.
3. 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.
Persons Recommended for Booster Vaccination
4. Healthcare and frontline workers are more likely to come into regular contact with COVID-19 cases in the course of their work and are at greater risk of infection. Many healthcare and frontline workers were vaccinated at the start of our National Vaccination Programme. Healthcare and frontline workers vaccinated then were observed to have a 1.4 to 2 times greater risk of being infected in the current surge. Furthermore, they may care for vulnerable persons such as the elderly and persons with medical conditions, and play a crucial role in maintaining our healthcare and frontline services. A booster vaccination in these workers would raise the level of protection of individuals in these groups and will preserve our healthcare capacity as well as frontline services critical to Singapore and our COVID-19 response.
5. Persons and staff in institutionalised settings, such as prisons and residential care facilities, are at risk of large COVID-19 outbreaks and some have already suffered such incidents. Some individuals in these settings may also be more vulnerable to COVID-19 complications. It is important to optimise protection in such populations against infection and minimise the risk of transmission in these settings by offering booster vaccinations. This will be an expansion from the previous booster recommendation for residents of aged care facilities.
6. In order to raise the overall population protection against infection and severe disease from COVID-19, a booster vaccination is now also recommended for persons aged 30 years and above.
7. At present, persons who have recovered from COVID-19 and were fully vaccinated before their infection, do not need a booster dose. Recovered persons who were unvaccinated, or partially vaccinated before their infection, should receive one dose of mRNA vaccine at least 3 months after infection to reduce their risk of reinfection, as part of their primary series vaccination. No booster dose is recommended yet, at this time.
Benefits Outweigh the Risks
8. Data thus far on booster vaccinations has shown that the safety profile of the third dose is similar to that for the first two doses, i.e., very safe. EC19V has assessed that the protective benefits of the booster vaccination, with a reduction in the risks of infection and severe disease, outweigh the risks of the additional dose in the recommended groups.
9. 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. Israel, with more than 2.5 million doses of booster vaccinations administered, has not observed a further increase in the risk of myocarditis/pericarditis with the booster dose thus far.
10. Persons younger than the age of 30 years old who are neither healthcare workers, frontline workers nor persons belonging to institutional settings are not yet recommended to receive the booster vaccination at this time. They would have completed their primary series vaccinations recently. Furthermore, relative to those working in the higher-risk settings, they generally do not have a greater risk of infection. They also have a low risk of developing severe disease from COVID-19 infection due to their younger age. EC19V will continue to monitor the data on booster vaccinations for this group, before making further recommendations.
11. Persons who are recommended for booster vaccination should receive a booster dose of a PSAR mRNA vaccine from about six months after the completion of their primary series vaccination with two doses. Priority should be given to healthcare and frontline workers due to their higher exposure risks. The prevailing minimum age criteria for the PSAR mRNA vaccines and medical contraindications will continue to apply.
12. Other vaccines available locally under the Special Access Route (SAR) should only be used according to WHO EUL’s approved age groups and indications, and currently there is inadequate data to support their use as booster vaccines.
Conclusion
13. EC19V will continue to monitor the global data and developments around COVID-19 vaccination and is assessing the suitability of booster vaccinations for other population groups, particularly persons under the age of 30 years.
EXPERT COMMITTEE ON COVID-19 VACCINATION
9 OCTOBER 2021