SINGAPORE - If you are thinking of dropping your guard and hoping to catch Covid-19 just to "get it over with" and "enjoy" the resultant immunity, you should think again, say experts.
After multiple waves of Covid-19 infections here, six in 10 residents are thought to have contracted the coronavirus at least once, Health Minister Ong Ye Kung told Parliament on Monday (Aug 1), adding that those who had a recent infection are less likely to get infected now.
But multiple experts told The Straits Times that this should not encourage people to try to catch the virus just for the sake of getting it out of the way.
"Even though the symptoms are mild, there is still a small number of people who need to be hospitalised," said Associate Professor Alex Cook, vice-dean of research and domain leader for biostatistics and modelling at the National University of Singapore's (NUS) Saw Swee Hock School of Public Health.
His colleague at the school, Associate Professor Natasha Howard, agreed.
Aside from the risk of needing to be hospitalised, she said it was still uncertain how long immunity conferred by infection would last.
Meanwhile, Associate Professor Ashley St John, from Duke-NUS Medical School's Emerging Infectious Diseases Programme, pointed out that complications, including "long Covid", can occur even in those who have been vaccinated against the virus.
"Individuals should continue to minimise their exposure to the virus to lower the risk of developing these complications," she said, adding that every transmission puts others at risk.
These include those at greater risk of severe illness, such as the elderly, immunocompromised, or very young children for whom vaccination is not yet approved.
Prof Howard, however, said that given most people here have been vaccinated or recently infected, the benefits of continuing to mandate indoor mask-wearing are "minimal".
Prof Cook emphasised that when a person is ill with Covid-19 or has a cold, they should wear a mask while interacting with others, and this should be a habit even in the post-pandemic world.
He noted that mask-wearing had reduced the risk of transmission among the small fraction of the population that was infectious but asymptomatic during the containment and mitigation phases of the pandemic, but said the question now is whether there is sufficient benefit to enforcing mandatory mask-wearing when people have no reason to suspect that they are infected.
"With over 90 per cent of the population vaccinated, and over half the population infected, there is little reason to contain the virus (and) there is no need to continue mandatory mask-wearing. There should be enough confidence to ease restrictions as Singapore has ridden the first wave without any other measures in place," he said, adding that isolation should continue to be encouraged for those with a communicable disease such as Covid-19 or the flu.
Prof St John said that whether or not indoor mask-wearing is mandatory, it is important to remember that doing so can slow the transmission of disease.
Adding that she personally still wears her mask indoors when in other countries where it is no longer mandatory, she said: "It is especially important to be vigilant and careful about mask-wearing when you may be interacting with those who are at high risk."
Mr Ong had also said during his speech that despite its infection rates, Singapore would never be able to hit herd immunity due to the speed at which the virus mutates, and that regular booster shots could become the norm here.
Prof Cook said that there are varying interpretations as to what "herd immunity" means. He pointed out that the understanding at the beginning of the pandemic - when there were hopes that the virus would not sustain itself once about half the population had been infected - no longer applies, but said that when cases start falling after a wave peaks, "fleeting herd immunity", which will be lost over time, can be achieved.
Prof St John, defining herd immunity as when "the immunity present in all of the individuals in the community works together to slow the spread of disease", said herd immunity is present, but imperfect, as a result of vaccines.
"We hope that with interventions like boosters or possible next-generation Covid-19 vaccines, we could improve herd immunity," she said.
Prof Howard emphasised that herd immunity as a form of permanent protection once a person is infected or vaccinated will not happen with Covid-19, and said there is a need for regular booster shots to combat the rapid mutation of the virus.
Prof Cook said that the cost of enforcing mandatory yearly booster shots, especially if they are part of the requirements for travel and entry into malls, would be quite high.
Noting that infections result in protection as well, he called instead for frequent vaccination to be "encouraged instead of obliged".
Prof St John said that future vaccines and their booster doses will be more effective in blocking transmission, especially of new variants of the virus.
While experts agreed there was no reason to assume the coronavirus would stop mutating, she said: "There are also precedents for eradicating viruses, like smallpox, based on developing strong vaccines... eventually there should be a tipping point where the virus cannot mutate to escape the pressure of the immunity we have collectively (acquired) - but we are quite far from that goal at this time."