Seniors taking COVID booster below six months after 2nd dose? ‘No concerns’: MOH

People wait at an observation area after their vaccination at a coronavirus disease (COVID-19) vaccination center in Singapore March 8, 2021. REUTERS/Edgar Su
People wait at an observation area after their vaccination at a coronavirus disease vaccination centre in March, 2021. (Reuters file photo)

SINGAPORE — There are no concerns for seniors who have completed their COVID-19 vaccination regime to receive their booster shots "slightly earlier" than the minimum recommended six-month interval after their second doses, said the Ministry of Health (MOH).

The ministry was on Tuesday (28 September) responding to Yahoo News Singapore's queries, following multiple accounts by those aged above 60 that they have been invited to receive their third vaccine shots under the national booster programme about five months after they took their second doses.

These seniors, who are not immunocompromised, were allowed to take them as early as the day after receiving a short message service (SMS) invitation for the booster shots.

"Individuals eligible to receive booster doses can expect to receive an SMS invite from around five months after their second dose, to provide some lead time for individuals to make an appointment," said MOH.

The ministry added that the expert committee on COVID-19 vaccination’s recommendation remains that those aged 50 and above should receive a booster shot at least six months after two doses.

"However, there are no concerns if an individual takes the booster dose slightly earlier than six months," said MOH, without detailing a specific time frame.

The expert committee had earlier announced that it recommended seniors to receive their booster shots six to nine months after two doses. Individuals who are immunocompromised have been recommended to receive them two months after.

Seniors who have taken their booster shots ahead of the official recommendation told Yahoo News Singapore that they have no health concerns arising from taking them prematurely, with one man in his early 60s saying he had no "special reason" to decline the invitation.

The interval between the man, who declined to be named, receiving his second and booster shots was about five months and a week.

Another senior said that he took the booster shot ahead of the six-month interval because of the recent surge in daily COVID-19 cases, which have been projected by authorities to hit 3,200 this weekend.

"Better safe than sorry," the 65-year-old man, who only wanted to be identified as Wong, said. The man received his second dose in late April and took his booster shot last week, less than five months later.

But not all are keen to take their booster shots too early. Leong, who declined to share his full name, said his 64-year-old mother had her second jab on 22 April and was sent an SMS invitation last Sunday to take her booster shot.

Instead of booking her appointment on Monday, she has decided to wait out the six-month period to observe the effects of such shots on other seniors, added Leong, 34.

Different country, different timeline for boosters

Singapore's booster vaccine programme began some two weeks for those aged 60 and above who had completed their vaccination regimen at least six months ago. Almost 91,500 seniors have received their booster doses as of last Thursday.

Last Friday, authorities announced those aged 50 to 59 who are eligible will be progressively invited from 4 October to receive their booster doses.

Only mRNA-based vaccines, developed by Pfizer-BioNTech and Moderna, are used in Singapore's national vaccination drive and by extension, its booster programme. While these vaccines have been granted interim authorisation under the pandemic special access route in Singapore, they have not been fully registered.

Under Singapore's booster programme, those who have been fully vaccinated with the Pfizer vaccine can opt to take a third shot of the Moderna vaccine, and vice versa.

To date, 82 per cent of Singapore's population have completed their full regimen or received two doses of COVID-19 vaccines, and 85 per cent have received at least one dose.

The city-state is among several countries that are already offering or planning to offer their populations COVID-19 booster shots, particularly for older adults and those with weak immune systems, as a number of studies show vaccine efficacies wane over time.

But timelines for booster shots differ from country to country, with some offering them as early as from four months to nine months after second shots.

Israel, the first country to start administering such shots, give them to those vaccinated at least five months after their second doses. The US had initially proposed to administer a booster at least eight months after a person is fully vaccinated but later revised it to six months.

Likewise, those in France and the UK can get the shot following a minimum six-month period after they are fully vaccinated with the Pfizer or Moderna vaccine. In Hungary, people have been advised to wait for four months after their second doses, regardless of age, health, or which vaccine they receive initially.

Austria on the other hand plans to begin its booster programme in October, nine months after the first group of people received their second doses.

However, there is no consensus yet among experts and agencies on whether a third dose is necessary.

The World Health Organization (WHO) in August said that current data do not indicate a need for booster shots and has repeatedly called for a delay, arguing that the most vulnerable people worldwide should be prioritised for full vaccination before high-income countries deploy third shots.

“Vaccine injustice and vaccine nationalism”, where vaccination rates are not raised globally, increase the risk of more contagious variants emerging, WHO director-general Tedros Adhanom Ghebreyesus said.

Those whose immune system is compromised should get booster shots, though they only represent a small percentage of the population, he added.

SDP's Paul Tambyah on MOH's stance

In response to queries from Yahoo News Singapore, Paul Tambyah, president of the US-based International Society of Infectious Diseases, said the reason for allowing seniors to take their booster shots in a shorter interval is due to the current surge in cases in Singapore.

The epidemiologist said, "The numbers are a little concerning so perhaps they (MOH) want the immunity of the seniors boosted even before the data are available."

On the expert committee's recommendation for an interval of between six and nine months after two doses, Dr Tambyah said MOH need not strictly abide by it as there is a shortage of scientific data on the issue, as seen by the fierce debate in the US.

Nonetheless, MOH's stance that residents can get their booster shots slightly before six months from their second doses is "reasonable" given the lack of data, he added.

His comments come on the same day when the Singapore Democratic Party (SDP) outlined an eight-point plan to exit the pandemic, which was drawn up by an SDP healthcare panel led by Dr Tambyah, who is the party's chairman.

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