SINGAPORE – Covid-19 is “permanent” and subsequent waves of infection will occur normally in the coming years, Singapore Foreign Minister Vivian Balakrishnan told CNBC.

“Covid-19 is endemic to humanity, which means it will never go away completely,” Balakrishnan told CNBC’s Squawk Box Asia on Monday.

“And the reason it won’t go away completely is because it’s spread around the world, has sufficient critical mass, the rate of mutations and new variants continues, and the level of human immunity increases and decreases as well,” said he said.

The minister, who was a doctor before entering politics, also warned that now could be a “more dangerous time” for vaccinated people who might be complacent, as well as those who are not vaccinated and have no protection against Covid.

Balakrishnan said vaccination is critical and that people who have received Covid shots develop fewer symptoms and have fewer serious illnesses, even when infected. However, vaccination alone is not the panacea for an “exponential explosion” in Covid cases.

That means measures such as social distancing and border restrictions may have to “come and go” in response to waves of Covid infection over the next two years, the minister said.

Singapore tightened social restrictions over the weekend after the number of cases increased in the community. Cumulatively, the country confirmed more than 61,300 cases and 31 deaths on Sunday, data from the Ministry of Health showed.

Balakrishnan said around 20% of Singapore’s population has been vaccinated, but the government has no defined threshold for achieving “herd immunity”. He explained that with the emergence of new variants of Covid, the level of protection required in a community will change so that the disease no longer spreads quickly.

It is likely that immunity to vaccinations will also decrease over time. So the point is, you can’t wait to say that you have reached the magical figure and suddenly you are immune and the mask has taken off and there are no restrictions.

Vivian Balakrishnan

Singapore’s Foreign Minister

“As new variants evolve and these new variants actually appear to be more contagious than the original strain, the level of herd immunity will mathematically change,” Balakrishnan said.

“It’s likely that immunity to vaccinations will also wear off over time. So the point is, you can’t expect to have reached the magical figure and suddenly be immune and mask off and not have any restrictions,” said he added.

Singapore-Hong Kong travel bubble

Singapore is a Southeast Asian city-state with no domestic air travel market. The country has reached an agreement with Hong Kong – a city that also has no domestic flight market – to create a travel bubble that will allow travelers to skip the quarantine.

When CNBC asked if the program should start on May 26th, Balakrishnan said, “As of now, the plan is yes, but we have to see how the situation develops over the next few days.”

The launch of the air travel bubble – originally scheduled for November 2020 – has been postponed several times after a surge in coronavirus cases in Hong Kong.

The two cities announced last month that the program will begin with one flight per day to each city with up to 200 travelers per flight.