Singapore experiencing new COVID-19 wave, more people expected to fall sick in coming weeks: Ong Ye Kung

Among those who are “best protected” – those who have the minimum of three mRNA shots and a natural infection within the last 12 months – the severe illness incidence rate is about 10 per 100,000 people.

For the “least protected” group, or those who have no minimum protection and no recorded infection, they are five times more likely to fall very sick when infected with COVID-19. The incidence rate for such individuals is more than 50 in 100,000 people.

He then moved on to another finding which he described as the “most important”. 

He said: “For individuals who are well-protected with three mRNA shots plus an infection, but these are all acquired more than 12 months ago, their incidence rate of severe illness is also about 50 per 100,000 population – not very different from those who have no vaccination or protection.

“This is a clear indication that protection wanes. And it happens at around the 12-month interval, based on our study.”

Mr Ong urged seniors and those who are medically vulnerable to keep their vaccinations up to date, adding that doing so will likely keep symptoms mild and allow them to “recover quite uneventfully” should they get infected.

The infection will also give them protection against severe illness if they are infected with COVID-19 again in future.

“Before this protection wanes, if you take another jab, the protection gets renewed again,” he said.

“However, if you are not up to date with your vaccination, and you allow your protection to completely wear off, an infection now can be as worrisome as when the pandemic first broke out, when we had no vaccinations.

“That is why MOH continues to offer COVID-19 vaccinations for free at our various vaccination centres.”