SINGAPORE - To keep the population safe from Covid-19, it is best for 70 per cent to 80 per cent or more of the population here, including close to 90 per cent of the elderly, to be vaccinated against the disease, said Health Minister Ong Ye Kung on Thursday (July 1).
Seniors are at higher risk of falling seriously ill and dying from the disease, and the higher vaccination numbers are necessary, as children aged below 12 cannot be vaccinated for now, while new and more transmissible variants are spreading.
The number of children who are aged up to 11 years is slightly below 506,000.
"Ninety per cent would be very hard to reach, but I'm really hoping that for the most vulnerable groups - the seniors - we can approach a figure somewhere near there," he told The Straits Times.
"Two-thirds fully vaccinated by National Day, I deem it an interim milestone. We can and need to go further than that."
Beyond National Day, Mr Ong said, 70 per cent to 80 per cent of the population could perhaps be vaccinated, though this depends on the "willingness of our people".
"And if young children can get vaccinated, it will help bring the number higher," he said.
Mr Ong noted that experts have said that 80 per cent or more need to be vaccinated to achieve herd immunity against the Delta variant of Covid-19, which is the dominant strain in Singapore, and is more transmissible than other strains.
"You may have future variants as well. So I think herd immunity becomes a concept that is inversely proportionate to the transmissibility or the R-naught of the variant."
Reproduction number, or RO, is the average number of infections generated by each case.
Herd immunity occurs when a large portion of the community becomes immune to a disease, making the spread of disease from person to person unlikely. So the whole community becomes protected, not just those who are immune.
"That doesn't mean the battle will be lost because you can still have an endemic Covid-19 (without) herd immunity.
"People will still get infected, but they will be fine. And so you make Covid-19 more like influenza. You can't make Covid-19 like measles, for example, where you try to eradicate it," said Mr Ong.
When contacted, Professor Teo Yik Ying, dean of the Saw Swee Hock School of Public Health at the National University of Singapore, said: "Herd immunity is actually not a binary concept, in the sense that once we surpass some estimated threshold for herd immunity, the community suddenly becomes safe from large outbreaks."
Instead, the extent and speed of reopening are linked to the risk of infecting the unvaccinated, and thus depend on how quickly Singapore is able to vaccinate the population, said Prof Teo.
"So, for example, if we hit 50 per cent with both doses, we may relax certain measures. When we hit 60 per cent or 70 per cent, there will be other kinds of relaxation, and eventually, working towards a lifting of most, if not all, the restrictions," he said.
"And if the high-risk groups are adequately protected, then even if the vaccination rate for the lower-risk group is still catching up, there can also be more easing of restrictions."
Prof Teo said that in living with Covid-19, the right thing to do is to make sure everyone eligible for vaccination is able to receive it. This ensures that individuals are protected, and collectively, the entire community is protected too, he added.
Read more from ST's exclusive interview with Health Minister Ong Ye Kung:
- S'pore could ease dining in rules from July 12 under 3-step plan
- Leisure travel may resume year end
- Getting Covid-19 could soon mean an MC, isolation and self tests
- Masks to remain key even in new normal
- Perks for those vaccinated against Covid-19 not meant to be discriminatory
- 'Sleep, exercise, work, eat': Ong Ye Kung on life amid Covid-19