SINGAPORE - Given that the majority of Singapore's population is now vaccinated against Covid-19, is it advisable for people to actively seek out infection in order to build immunity, as some used to do with chickenpox?
The answer is a firm "no", said Associate Professor David Lye of the National Centre for Infectious Diseases (NCID).
While vaccination reduces the long-term side effects of infection, it does not eliminate them altogether, he said in response to a question at a webinar on Monday night (Feb 21).
In addition, the elderly and those with poor immunity are still likely to get very sick, even though the Omicron variant is milder than its Delta predecessor.
When these people flood hospitals, other patients will get displaced and also suffer, said Prof Lye, who is director of NCID's infectious disease research and training office.
"Omicron is definitely a blessing compared with Delta, but it is not time to have an Omicron party," he added. "We are a lot more cheerful in 2022, but it will still hit the vulnerable."
Prof Lye was one of five panellists at a webinar organised by the National University of Singapore's (NUS) Yong Loo Lin School of Medicine.
During the two-hour session - titled "The new normal: A moving target?" - speakers addressed topics such as vaccination, virus mutations and the lessons to be learnt from the past two years.
They also discussed new treatments for Covid-19, such as Pfizer's Paxlovid pill, and the importance of making sure the entire world is protected against the virus.
Professor Teo Yik Ying, dean of the NUS Saw Swee Hock School of Public Health, warned that this year is likely to see a "pandemic of the unvaccinated" as countries ease restrictions and open borders.
When Covid-19 first hit, countries relied on measures such as lockdowns to protect their populations from the virus, he said. Now, most are relying on vaccines to mitigate the severity of Covid-19 infections, thus allowing them to lift many restrictions.
"For the unvaccinated, this means the chance of contracting Covid-19 will, in fact, be the highest ever, unless one self-imposes a routine of staying indoors and minimising any public movements - which clearly is impractical for most people."
Prof Teo and the other speakers also highlighted the gulf in vaccination rates and access to Covid-19 treatments between developed countries such as Singapore - where 91 per cent of the total population is now fully vaccinated - and the developing world.
In contrast, fewer than one in 10 people in Nigeria and Ethiopia has been fully vaccinated.
"There will be some countries that will be able to recover and return very much to life before Covid-19," he said. But many others will have to build natural immunity through infection, meaning that some people will suffer long-term consequences to their health.
This ties in with recent talk that people may potentially need further booster shots, said Dr Jyoti Somani, a senior consultant at the National University Hospital's infectious diseases division.
Some countries, such as South Korea, are planning to start administering fourth doses of the Covid-19 vaccine, in what amounts to a second booster shot.
But countries should not be giving any additional booster shots, except perhaps to people with weakened immune systems, Dr Somani said.
"We can't just keep giving ourselves boosters. We need to vaccinate the rest of the world."