SINGAPORE - Omicron's mortality rate is lower than Delta's but the high number of cases in recent months has contributed to more deaths in Singapore, especially among the unvaccinated, experts said.

There were 95 deaths from Covid-19 between January 2020 and September last year.

But the country has recorded another 1,058 Covid-19 deaths since Oct 1 last year.

Professor Leo Yee Sin, executive director of the National Centre for Infectious Diseases (NCID) said the denominator, or the number of people who were infected, is an important consideration.

With vaccination and a milder Omicron variant, the mortality rate is five to six times lower than when the more virulent Delta variant was dominant, she added.

Professor Dale Fisher, a senior infectious diseases consultant at the National University Hospital, said the surge since September came after restrictions were eased in August.

Together with Omicron being more easily transmitted, many more people, including seniors who remain unvaccinated, were infected.

"The death rates were remarkably over-represented in the unvaccinated," Prof Fisher added.

"Whether it's (people) on oxygen, in intensive care units, or deaths, the unvaccinated, even though it's only 5 to 10 per cent of the population, was still more than 50 per cent of all the cases."

The two experts were among three panellists who spoke on Tuesday (March 15) at a discussion titled Covid-19 Restrictions: When Can They Be Eased Further.

It was held at SPH Studios in Toa Payoh and moderated by The Straits Times' senior health correspondent Salma Khalik.

The third panellist, Professor Teo Yik Ying, dean of the Saw Swee Hock School of Public Health at the National University of Singapore, agreed that the current wave has been a problem for the unvaccinated.

He said: "The fully vaccinated plus boosted people continue to remain at a 21-fold protection against anyone that is unvaccinated."

However, Prof Leo pointed out that vaccination notwithstanding, "the older you are, the higher the risk; the more chronic conditions you have, the higher the risk".

She added: "Vaccines will reduce the risk, but it cannot completely take away that risk."

Prof Leo said more than half the Covid-19 patients at the NCID are over the age of 60.

"So we know that this particular segment of the population, despite having full vaccination, two doses, or being boosted with a third dose, they remain a vulnerable population."

Prof Fisher said a consideration going forward is how such individuals can be protected without impacting on the whole of society.

Prof Teo's solution is for greater personal responsibility.

He said: "If I'm going to visit my parents, my elderly grandmother, or if I'm going to have meals or gatherings with an elderly person, I take that personal responsibility.

"I test myself before I go."