Vaccinations are a more sustainable way of protecting the population, though the current slew of Covid-19 curbs - while fairly aggressive - are necessary, experts said.

It is gratifying that the nation stopped short of a circuit breaker, which will otherwise signify that Singapore can no longer control the virus' spread, Professor Dale Fisher, an infectious disease expert from the National University of Singapore's (NUS) Yong Loo Lin School of Medicine, said on Tuesday.

"But I believe we would have a circuit breaker in place if there was no vaccine," said Prof Fisher, who is also the chair of the World Health Organisation's Global Outbreak Alert and Response Network.

He added that Singapore's moderately high vaccination rate of over 30 per cent of the population, which includes those who have already received their first jab, is a game changer in helping the nation avoid another circuit breaker.

The speed at which clusters have grown, such as the largest one in Changi Airport - which has ballooned to more than 80 cases over just two weeks - coupled with more unlinked cases and the growing number of active clusters, are some of Singapore's worrying Covid-19 trends.

But re-entering a circuit breaker - which would bar intermingling between different households - would give the authorities time to understand what is happening in the community and let healthcare facilities recuperate and reduce their load, Professor Teo Yik Ying, dean of NUS' Saw Swee Hock School of Public Health, said at a webinar.

The webinar, organised by the NUS Yong Loo Lin School of Medicine, was hosted by Associate Professor David Allen.

It also featured Dr Louisa Sun, an associate consultant with the infectious diseases team at the National University Hospital and Alexandra Hospital, and Associate Professor Hsu Li Yang, vice-dean of global health at the Saw Swee Hock School of Public Health.

The experts took a deeper look at current restrictions - such as the complete shift to home-based learning (HBL) in schools - which have been disruptive.

HBL was done as a precautionary measure, given that the B1617 variant is more likely to infect children.

Prof Teo said HBL is not a long-term strategy.

Instead, vaccination of children, where those aged 12 to 15 can now get the Pfizer-BioNTech shot in Singapore, will be a more sustainable way of protecting them in the long run.

Home-based learning and school closures increase inequity because families that are more able to cope will do better, while other parents may struggle to make sure their children can keep up with the curriculum, as well as to supervise them.

"HBL is just a way for us to tap the brakes, learn a bit more about the chains of transmission that are happening in schools, but it is not going to be a long-term strategy," Prof Teo said.

Other strategies, such as rostered routine testing, are also not part of a viable long-term strategy because of the tremendous costs, inconvenience and low yield, Prof Hsu added.

"But as a way of preventing transmission to more vulnerable members of the community and providing assurance that measures are in place, it sends a good message.

"But in the long run, we will probably not be able to sustain it," Prof Hsu said.

When asked if Singapore should adopt a zero-tolerance approach to Covid-19 or learn to live with it as an endemic disease, the panel felt that the endpoint of this pandemic will realistically see Covid-19 becoming an endemic disease.

"We are going to need high levels of vaccination which will reduce Covid-19 to a fairly mild disease which can circulate around," Prof Fisher said.

He added that much work remains in helping the community understand that Covid-19 is heading towards becoming an endemic disease and to accept the presence of cases and clusters.

A zero-tolerance strategy will mean extremely strict border controls which will create an artificial sense of stability and safety, a strategy that would not last long for many countries, Prof Teo added.

"Vaccination was designed to minimise serious symptoms and side effects but not meant to completely block the risk of infection.

"If we are vaccinated, then get infected and are asymptomatic, and do not have a risk of going to the hospital or suffer from a serious side effect - that looks like one of the ways of living with the disease in the long term," Prof Teo said.

Prof Hsu pointed out that in the history of human diseases, such as measles and tuberculosis, mankind has learnt to live with them, with the help of vaccination.