Dr Leong Hoe Nam from Rophi Clinic at Mount Elizabeth Novena Specialist Centre is of the view that vaccine boosters should be used whenever it can reduce deaths or serious illnesses.
He finds the decision to give boosters to seniors aged 60 and above “a rather rough tool”.
Although he recognises that a booster will help a diabetic suffering from kidney failure, it is “unlikely to really benefit” a 69-year-old man with no history of chronic illnesses.
In the meantime, he warns against taking booster jabs too often because the body may treat the vaccine as "self", learn to tolerate it and then not respond to fight the virus.
“That would be the greatest disaster. The body’s immune system would then ‘welcome’ the real infection with no resistance,” he said.
Similarly, Dr Paul Tambyah, president of the Asia Pacific Society of Clinical Microbiology and Infection, does not see booster shots as necessary for the entire population for now, because there are still many unknowns such as how long protection from a booster shot would last
He pointed out that an Israeli study published in the New England Journal of Medicine looked only at the first 12 days after the third shot and it showed that the third dose was around 90 per cent effective against both severe disease and any confirmed infection.
“I think that there are other options such as studying a longer interval between doses or a mix-and-match approach, and these were studied in the UK and South Korea,” he said.
“We need to see the data before making broad decisions. For now, I think focusing on the immunocompromised is reasonable.”