What you need to know about vaccine booster doses for those who test positive for COVID-19

SINGAPORE: Do I need to take a vaccine booster dose if I test positive for COVID-19 on an antigen rapid test (ART) at home?

What if I have taken mRNA (PfizerBioNTech/Comirnaty or Moderna) and non-mRNA vaccines (Sinopharm or Sinovac) and have been infected? Do I still need a booster shot?

These are some of the queries the Ministry of Health (MOH) on Saturday (Jan 29) said it received regarding booster vaccination doses.

With those aged 18 and above required to take a booster shot - in addition to their primary series of COVID-19 vaccination - from Feb 14 in order to be considered fully vaccinated against COVID-19, here's what you need to know if you have tested positive for the coronavirus.

Should I get a booster shot if I test positive for COVID-19 on an antigen rapid test (ART)? 

Those found to be COVID-19 positive after performing an ART self-test, or via rostered routine testing or pre-event testing will still need to get their booster dose, said MOH.

This is because in these cases, the Health Ministry has no record of their infection as they typically fall under Protocol 2 - where patients must isolate themselves for at least 72 hours after testing positive for COVID-19 and can only leave their homes if they test negative on the third day. 

In such cases, individuals are recommended to take their booster shot about five months after the last dose of their primary vaccination series so as to extend the validity period of their full vaccination status beyond the initial 270 days.

Do I need a booster injection if I have been infected with COVID-19 after my first two vaccination jabs? 

"The default is yes," said MOH.

While those infected with Omicron are presenting mild symptoms with lower viral loads, a booster dose will grant longer protection from COVID-19, said the Health Ministry. 

It is safe for people who have recovered from the disease to receive a booster dose, based on recommendations by Singapore's expert committee on COVID-19 vaccination, it added.

Those with prior COVID-19 infections will not be turned away from vaccination centres, MOH said. 

Can I choose not to take the booster shot after recovering from COVID-19? 

Individuals whose COVID-19 infection is reflected in their HealthHub records - after they have seen a doctor when they were infected or were detected to be positive for the virus when travelling into Singapore - can choose not to get a booster shot.

Their infection can be considered as a booster dose and "the update of your status is automatic, and no action is required on your part", said MOH.

Do I need a booster if I had taken mRNA and non-mRNA COVID-19 vaccination doses and been infected? 

MOH noted that it has received many queries on the need for boosters after various permutations of mRNA vaccine doses, Sinovac or Sinopharm vaccine doses and infections.

It said the answers to these questions are "complicated and depend on the order and timing between these occurrences".

To this end, MOH is working on a calculator for its website which will help individuals determine if they need to take boosters to extend their validity period.

The rule of thumb is that two doses of an mRNA vaccine or three doses of either Sinovac or Sinopharm confer full vaccination status for 270 days, the ministry said, adding that a booster or an infection documented in its records after that will extend the validity of vaccination. 

If I have a positive serology test result, do I take a booster shot? 

A positive serology test does not provide a good basis to decide if the individual can be exempted from boosters, MOH said, adding that a positive result can be generated due to vaccinations or infections, without clear indication of timing. 

"MOH would also like to advise individuals against taking serology tests to try to exempt themselves from a booster dose."

A serology test is not a "strong indication of resilience against severe illness" caused by the virus, it added.

"When in doubt, please come forward to receive a booster dose and get yourself properly protected."