Health Minister Gan Kim Yong said authorities are monitoring the hospital cluster closely and the next few days were critical. “If we find many more cases that suggest widespread transmission, we will have to introduce more measures to break the chain of transmission,” said Gan.

The hospital has already shut down four wards and will test all its staff for Covid-19. The patients in the four closed wards have so far all tested negative. Staff will work in cohorts, and all discharged patients and visitors who were at the hospital from April 18 will be surveilled by authorities. Public places visited by the hospital cases during their infectious period will be closed for two days for cleaning. These include restaurants, supermarkets, a church and mosques.

Education Minister Lawrence Wong, who co-chairs the virus task force with Gan, said Singapore had to be prepared that if the situation were to worsen “we may have to consider further tightening and significantly reducing interactions in the community with more stringent measures”. He said authorities will pay attention to unlinked cases found in the community as well as compliance with safe management measures.

Of the 13 cases at the hospital, four of the staff and one of the patients were fully vaccinated while another patient had received one dose of the vaccine. Director of medical services Kenneth Mak said investigations so far found that there were no issues with the quality of the vaccines these people had received. Singapore has been using vaccines from Pfizer-BioNTech and Moderna.

Wong said residents should not overreact to news of vaccinated people catching the virus nor make the mistake of thinking that vaccinations do not work. “I think that would be disastrous because the vaccinations do work,” he said.

TRAVEL BUBBLE

In response to a question from This Week in Asia on whether the situation in Singapore would affect the quarantine-free travel arrangement, Wong said the bubble suspension mechanism would not change. However, he added that travellers must be “mentally prepared” that the “fluid” situation could change, and the bubble would not start if Singapore reached the threshold before May 26.

“It’s highly unpredictable, there will be ups and downs in our infection controls from time to time,” said Wong.

Currently, Singapore’s seven day moving average of unlinked cases was 1 as of Thursday night, while Hong Kong’s was 0.29 as of Friday.

Explainer | What you need to know about the Hong Kong-Singapore travel bubble

The growing hospital cluster is among the handful of active coronavirus clusters that Singapore has recently discovered. Another involved a group of recovered migrant workers who were all staying in the same mega-dormitory. They were linked to a 35-year-old Bangladeshi worker who caught the virus despite being fully vaccinated.

Health authorities provided an update on Friday, saying that 27 recovered migrant workers had again tested positive for the virus. Of these, 20 are shedding virus fragments of old infections, which they earlier said were non-infectious. Two were later tested negative, and five were determined to be likely reinfections.

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Travel bubble: Hong Kong and Singapore to launch quarantine-free entry after long delay

Travel bubble: Hong Kong and Singapore to launch quarantine-free entry after long delay

Regarding the tightened border restrictions, Wong, the co-chair of the task force, said Singapore has been monitoring the situation in India but it “unfortunately has continued to deteriorate, and we know that the infection is spreading beyond India to the surrounding countries”.

Visitors entering Singapore from Thailand could previously opt out of serving their two-week quarantine period at a dedicated facility, but will no longer be able to.

But those arriving from Fiji and Vietnam would still be allowed to serve their 14-day stay-home notice at their place of residence, provided they live there alone or are with household members who are also serving the same isolation period, authorities said.