No recreational travel is likely this year or early next year as countries that are still knee-deep in the Covid-19 pandemic continue to play safe and keep tourists away.
Speaking at The Straits Times Covid-19 webinar, Professor Teo Yik Ying, dean of the National University of Singapore's Saw Swee Hock School of Public Health, said: "When we (travel), we end up being exposed to many different factors that are beyond our control."
Answering a question posed by a participant, he noted that Covid-19 transmission could take place on the plane, at the hotel, or at local tourist attractions.
Citing the example of Australia, he said the country had almost won the battle against Covid-19 last month but fresh outbreaks have now been reported in Melbourne and New South Wales.
"If we look at what's happening in Hong Kong and Australia right now, the situation changed very quickly within a matter of two to four weeks.
"So, when it comes to mass market tourism, regrettably, I think we will not be able to travel out of Singapore for the foreseeable future," Prof Teo added.
He suggested taking a staycation in Pulau Ubin or Sentosa instead.
His comments come a few days after National Development Minister Lawrence Wong said leisure travel was unlikely this year, although essential business travel was possible.
Last Friday, Mr Wong, who co-chairs the multi-ministry task force tackling Covid-19, said it is unlikely that the infection worldwide will disappear by the end of the year, making travel risky.
However, negotiations with countries on reciprocal green lane arrangements will continue, to allow for essential business travel as long as mutual control measures are in place.
Weighing in on the discussion during the webinar, Professor Dale Fisher, a senior infectious diseases consultant at the National University Hospital, noted that theoretically, leisure travel is possible between like-minded countries.
The key is trust in each other's healthcare systems and processes, as well as the management and containment of Covid-19 cases.
Prof Fisher said: "For instance, we would be comfortable with China because as soon as they get a case, they will lock down the whole area, swab everyone within a certain radius, and we could be comfortable that China is not going to send any potential Covid-19 cases to Singapore."