askST: What you need to know about Singapore's new Covid-19 vaccination strategy

As part of Singapore's new approach, vaccination is based on being up to date, rather than on the number of doses taken. ST PHOTO: SYAMIL SAPARI

SINGAPORE - Singapore is transitioning to a new strategy for Covid-19 vaccinations, with a focus on being up to date, rather than based on the total number of shots received.

At the same time, the Government has lifted all remaining vaccination-differentiated measures, including removing the requirement for vaccination for events with more than 500 participants or dining in at eateries.

What does this mean for those who are thinking of whether to get a second booster?

The Straits Times has the answers.

Q: How many doses of a Covid-19 vaccine am I now required to take?

Singapore now requires that people get two shots of an mRNA vaccine, with an additional booster dose administered at least five months after completing the primary series of the first two shots.

As things return to normality, the country will also transition to a new strategy of up-to-date vaccination, instead of counting the number of shots and boosters individuals receive. This is a similar approach to how influenza vaccinations are administered seasonally.

Individuals will be considered up-to-date with their Covid-19 vaccination if they have received at least the minimum protection. This comprises three doses of an mRNA vaccine or the Novavax/Nuvaxovid vaccine, or four shots of Sinovac-Coronvac or Sinopharm vaccines. They must have received their last vaccine dose within the past year.

- After achieving minimum protection - those aged 50 years and above should receive an additional booster dose of an mRNA vaccine between five months and one year from their last dose.

- Those aged five to 11 years old should complete three mRNA doses to achieve minimum protection. They can receive a booster dose of the Pfizer-BioNTech/Comirnaty vaccine five months after the second dose. It is the only Covid-19 vaccine recommended for this age group.

- Those between six months and four years should take two doses of the Moderna Spikevax vaccine at least eight weeks apart, or three doses of the Pfizer-BioNTech/Comirnaty vaccine, with the first two doses three weeks apart and a third dose at least eight weeks after the second. The Pfizer BioNTech/Comirnaty vaccine for children below five should be available end of this year. No boosters are recommended for this age group yet.

Q: What are bivalent vaccines and who should take them?

The bivalent Covid-19 vaccines include a component of the original virus strain to provide broad protection against Covid-19 and a component of the Omicron variant to provide better protection against the Omicron strain.

The Moderna bivalent vaccine approved by the Health Sciences Authority (HSA) in September targets the original Sars-CoV-2 strain of the virus as well as the Omicron BA.1 variant. 

At the time, HSA said preliminary data suggested that the Moderna bivalent vaccine was also effective against the Omicron BA.4 and BA.5 variants, and others such as the Delta and Gamma variants.

The Expert Committee on Covid-19 Vaccination has recommended the use of the bivalent vaccine to replace the existing formulation.

This means the original Moderna Spikevax vaccine will be replaced with the bivalent version starting Friday, and made available for people aged 18 and above.

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People aged 50 or older, as well as those who have yet to get basic protection against Covid-19, should have the bivalent vaccines, MOH said.

Pfizer’s bivalent vaccine is still under evaluation, but is expected to be available in Singapore by the end of the year.

Q: I have already taken my primary series of two mRNA jabs and a booster shot. Do I still need to get additional shots of the Covid-19 vaccine?

Yes, you will have to at some stage. A study by the United States Centres for Disease Control and Prevention, published in February, showed that the effectiveness of mRNA boosters declined substantially after four months, suggesting the need for additional shots.

With new variants of the coronavirus expected to emerge with the approaching winter in the northern hemisphere, Health Minister Ong Ye Kung said those eligible should get their shots.

MOH now recommends that only those 50 and above get a booster shot between five months and a year from the last dose, but it added that it will consider extending this recommendation to other age groups at a later date.

Q: Will non-mRNA vaccines still be available?

The Novavax/Nuvaxovid vaccine remains available at the joint testing and vaccination centre in Bishan, as well as the Yishun and Jurong polyclinics.

The Sinovac-CoronaVac vaccine was earlier available as a booster for only those medically ineligible to receive the mRNA and Novavax/Nuvaxovid vaccines.

Now, people who have yet to receive a booster dose can be given the Sinovac vaccine as a booster, even if they are not medically ineligible for other vaccines.

However, the Expert Committee on Covid-19 Vaccination still recommends they consider taking either the mRNA vaccines from Moderna and Pfizer-BioNTech or the Novavax vaccine as a booster due to the better protection conferred.

Correction note: An earlier version of this article stated that those aged five to 11 should complete three mRNA or Novavax/Nuvaxovid doses, or four Sinovac-CoronaVac doses to achieve minimum protection, and that they can receive a booster dose of the Pfizer-BioNTech/Comirnaty vaccine five months after the last dose. This has been corrected.

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