SINGAPORE, Sept 3 — Immunocompromised persons and the elderly will be eligible for booster Covid-19 vaccination shots starting sometime this month, depending on when they had their earlier two doses, to ensure that they are sufficiently protected from severe illness from the virus, said the Ministry of Health (MOH) today.
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 today, Health Minister Ong Ye Kung, who co-chairs the multi-ministry task force tackling the Covid-19 situation, 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 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”, said MOH. The three-dose programme will ensure that they have an “adequate immune response”.
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 during September.
“Seniors are also at risk of severe Covid-19 infection and may develop a lower immune response from their two-dose vaccination regimen,” said MOH.
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, said MOH.
More details on the implementation of the booster shot will be announced at a later date.
With the more transmissible Delta variant, MOH said that 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.
While global evidence has continued to show that vaccines are effective in reducing severe illness and deaths, some countries have decided to proceed with booster shots.
MOH added that the additional 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 also approved a third dose for immunocompromised individuals and is considering its recommendation for seniors, MOH said.
The authorities announced on Tuesday that Singapore will send 500,000 doses of Pfizer-BioNTech Covid-19 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.
Vaccinations still effective, but boosters to pre-empt waning immunity levels
During the press conference, Ong added that vaccines continue to be effective because while the number of antibodies may wane, there are memory cells in the body that will learn how to produce new antibodies.
He compared the process to a student preparing for an exam.
“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,” said Ong, who was formerly Minister for Education.
However, he said that it was recognised that immunity wanes over time, with increasing breakthrough infections, that is, vaccinated people who get infected. In “absolute terms” this means more 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,” said Ong.
“This is especially relevant to the elderly and other higher risk groups.” — TODAY