SINGAPORE: Singapore will "very likely" have to start a COVID-19 vaccination booster exercise, said Health Minister Ong Ye Kung on Thursday (Aug 19), adding that it will be necessary for people who are severely immunocompromised to get a third dose of the vaccine.
This includes patients on cancer treatment, transplant patients, patients on immunosuppressive therapy and end-stage kidney disease patients on dialysis.
"Because of their conditions, these persons react much less to vaccinations even after two doses, meaning they cannot produce as much antibodies or activate the necessary mechanisms to fight the virus," Mr Ong said.
"Hence a third dose of vaccine is necessary for them."
The Expert Committee on COVID-19 Vaccination will make its recommendations concerning this shortly, the Ministry of Health (MOH) said in a statement on Thursday.
MOH said it is also looking at the need to enhance the immune response of individuals who have a weaker immune response to vaccination despite completing a full vaccination regime.
This includes people who have an increased risk of getting infections even after vaccination, said MOH's director of medical services Kenneth Mak on Thursday.
"For example, they may have not mounted an adequate immune response to the original full two-dose regime, or they have a waning protection from vaccinations and therefore require augmentation of that immune response in order to give them further protection," he said.
This comes after Associate Professor Mak said on Aug 6 that the expert committee was discussing whether COVID-19 booster shots needed to be given to specific groups like seniors, vulnerable people and healthcare workers, or to the general population.
MOH said on Thursday that while a large proportion of the population is now vaccinated, it is planning ahead to ensure that people continue to be well protected from COVID-19 and its new variants as they arise.
"The Expert Committee on COVID-19 Vaccination has been reviewing and monitoring the local and overseas data on vaccine boosters and is developing recommendations on Singapore’s booster strategy," it said.
Mr Ong had said on Jul 8 that the booster exercise could begin around Chinese New Year next year.
The minister was responding to questions by members of the public about living with COVID-19 through an Instagram live broadcast, according to Chinese daily Lianhe Zaobao which reported on his remarks.
Pointing to examples in other countries, Mr Ong said on Thursday that Israel has started administering boosters to seniors and vulnerable people, while the UK, Germany and France will start in September.
The US Centers for Disease Control and Prevention has also recommended a booster shot eight months from the second dose.
"These countries started vaccinations, earlier than us, and we therefore now have the advantage of observing them and learning from their experiences," Mr Ong said.
Mr Ong said the expert committee is studying two "key things" before finalising its recommendations.
The first is the incidence of adverse reactions, and whether they will be lower or higher than the first or second dose. "If it is higher, what are the steps we can take to mitigate and remove the risk," Mr Ong said.
The second is whether the booster shot should be from the same brand of vaccine.
"There is scientific basis to suggest a heterologous strategy may confer stronger protection," Mr Ong said, referring to mixing different brands of vaccine. "The UK is implementing such a strategy, and we will be monitoring the outcome closely."
Mr Ong said there is "quite a sizeable group" of people in Singapore who took a first dose of mRNA vaccine and found out that they were allergic to it, before taking a second dose of Sinovac vaccine.
"The (expert committee) will be closely monitoring their immune response," he said.
Once the expert committee has finalised its plans, Assoc Prof Mak said authorities will then need to work through operational details like what type of vaccine will be provided, as well as how and when the supplies would be delivered.
Mr Ong said it is not surprising that some countries have started their booster exercise before Singapore, pointing to how they began vaccinating their population "a good two to three months earlier than us".
"In time, I believe the (expert committee) will come up with their recommendation to start our booster programme," he added.
Mr Ong also said that the vaccination of children below 12 should start sometime in early 2022. This would come after authorities have "properly studied the safety and efficacy aspects", he said.
As of Tuesday, MOH said 77 per cent of the population has completed their full regimen or received two doses of the COVID-19 vaccine, with 82 per cent receiving at least one dose.
"Vaccination continues to be a key part of our efforts to keep the community situation under control," the ministry said.