Immunocompromised persons, seniors to start getting Covid-19 booster vaccine shots in coming weeks: MOH

• Health Minister Ong Ye Kung said that the protection from vaccines will be reduced as antibodies wane over time
• Immunocompromised people will receive their third dose two months after the second dose, and the elderly will receive it after six to nine months
• MOH said booster shots have been adopted in other countries such as Israel and Germany

SINGAPORE — Immunocompromised persons and seniors will be eligible for booster Covid-19 vaccination shots starting sometime this month, depending on when they had their earlier two doses. This is to ensure that they are sufficiently protected from severe illness from the coronavirus, the Ministry of Health (MOH) said on Friday (Sept 3).

MOH said that the expert committee on Covid-19 vaccination had recommended this move based on the efficacy of booster doses administered globally.

At a press conference on Friday, Health Minister Ong Ye Kung, who co-chairs the Government's Covid-19 task force, said that while vaccines still offer protection against infection, the strength of the protection will “come down as antibodies wane several months after the vaccination”.

In its statement, MOH said that those who are moderately to severely immunocompromised will receive a third dose of the same messenger ribonucleic acid (mRNA) vaccine two months after their second dose as part of their primary vaccination course. 

This is because immunocompromised people have a “blunted immune response to vaccination and are also at a higher risk of severe illness from Covid-19”, it added.

The three-dose programme will ensure that they have an “adequate immune response”.

The expert committee elaborated in a statement later that there are studies showing that a third dose “increases the likelihood that immunocompromised persons develop a robust protective immune response”.

The immunocompromised include cancer patients on active treatment such as chemotherapy, those with end-stage kidney disease on dialysis, and those with advanced or untreated human immunodeficiency virus (HIV).

The committee added that immunocompromised people would be referred to receive the third dose by their doctors, who will have “the best understanding of their medical condition”. 

BOOSTER SHOTS FOR ELDERS

For seniors aged 60 years and above and residents of aged-care facilities, they should receive a booster dose of a pandemic special access route mRNA vaccine — the Pfizer-BioNTech and Moderna vaccines — six to nine months after completing their two-dose vaccination regimen.

The first batch of seniors aged 60 and above and who completed their two-dose regimen in March will be eligible for the third dose in September.

“Seniors are also at risk of severe infection and may develop a lower immune response from their two-dose vaccination regimen,” MOH said.

The ministry added that the booster shot will ensure higher levels of protection from infection and continued high levels of protection against severe disease.

It will also reduce the possibility of spikes in infections and more people falling severely ill.

The expert committee said that seniors may develop a lower immune response to the initial two doses of vaccines, and their immunity has also been observed to decline over time.

“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.”

More details on the roll-out of the booster shots will be announced at a later date.

OTHER COUNTRIES GOING AHEAD WITH BOOSTER SHOTS

With the more transmissible Delta virus variant, MOH said it is not likely that countries can achieve herd immunity without a very high population vaccination rate of “well over 90 per cent”, and that there has also been emerging evidence of the waning of vaccine efficacy over time.

Mr Ong also said that data in Singapore has shown that the ability of vaccines to prevent Covid-19 stands at just 40 per cent.

Global evidence has continued to show that vaccines are effective in reducing severe illness and deaths, but some countries have decided to proceed with booster shots.

MOH added that the extra dose recommendations for immunocompromised individuals, seniors aged 60 years and above, and residents of aged-care facilities are aligned to the vaccination measures adopted in countries such as Israel and Germany.

The US Food and Drug Administration has approved a third dose for immunocompromised persons and is considering its recommendation for seniors, MOH noted.

Earlier this week, the Ministry of Foreign Affairs announced that Singapore will send 500,000 doses of the Pfizer-BioNTech vaccine to Australia as part of a "dose-sharing" agreement.

Under the deal, Australia will send the same quantity of vaccines back to Singapore in December, which would potentially be used as booster shots.

Elaborating on the arrangement, Mr Ong said that it is a “win-win” for both nations. 

This is because Australia is ramping up its vaccination numbers during this period and will need more vaccines. 

At the same time, there are “not that many” seniors in Singapore who had been inoculated in February and March, so few will need a booster shot in September. 

“But as the months go by, the number will increase, and we might also extend (the booster shots) to a younger population,” he said. 

“This means that towards the end of the year and beginning of next year is when we need more vaccines, then Australia will be returning us… So this is a win-win arrangement.” 

BOOSTER SHOTS TO PRE-EMPT WANING IMMUNITY LEVELS

During the press conference, Mr Ong repeated the point that vaccines continue to be effective because although the number of antibodies may wane, there are memory cells in the body that will learn how to produce new antibodies.

The former education minister compared the process to a student preparing for an examination.

“When you prepare for an exam, you cram a lot of facts in your brain, and after you take the exam... you forget all the facts, but you are still left with every valuable education, skills, knowledge that you can use for the rest of your life,” he said.

“(The) cellular response through the memory cell is like your underlying education. It’s still very invaluable.”

However, he said it was recognised that immunity wanes over time with increasing breakthrough infections, that is, vaccinated people who get infected.

In “absolute terms”, this means that more people can fall sick and succumb to Covid-19.

“If your infection numbers go up very very high in absolute terms, you can still be looking at quite a number of people who are very, very sick or die, and we want to pre-empt that,” Mr Ong said. 

“This is especially relevant to the elderly and other higher-risk groups.”