SINGAPORE - Two of the three locally transmitted cases of Covid-19 reported on Friday (April 23) had received both doses of the vaccine, while the third had received one of two jabs.

The first - a community case - is a 38-year-old Indonesian man in Singapore for a work project, said the Ministry of Health (MOH).

His infection was detected at a pre-departure test on Thursday before his trip back to Indonesia.

The patient had been vaccinated in Indonesia - he received his first dose on March 4 and his second dose on March 18.

He arrived here on March 28 and served a stay-home notice (SHN) until April 11. He tested negative for the virus then.

The second vaccinated patient to test positive is from a foreign workers' dormitory.

He is a 21-year-old Indian national on a work permit, employed by Sembcorp Marine Integrated Yard.

The man stays at SCM Tuas Lodge and works at Sembcorp Marine Tuas Boulevard Yard.

His infection was detected on Monday when his pooled test from rostered routine testing came back positive.

He had received his first dose of Covid-19 vaccine on March 11, and his second dose on April 1. MOH said that this is likely to account for his lack of symptoms.

"The Covid-19 vaccine is effective in preventing symptomatic disease for the vast majority of those infected, but it is possible for vaccinated individuals to get infected," it said.

It added that further research is necessary to determine if the vaccine will prevent onward transmission of the virus.

The third locally transmitted case is in the community.

He is a 33-year-old man from Indonesia who is a crew member on a ship.

The patient had flown in from Indonesia on Feb 4. He tested negative on arrival and during SHN.

MOH said that he has not left his vessel except to be vaccinated.

The man received his first jab on April 16, but has not received his second dose of the vaccine.

"It is possible for one to be infected before or just after vaccination as it typically takes a few weeks for an individual to build up immunity after completing vaccination," said MOH.

All three cases are currently unlinked.

There were also 36 imported cases for a total of 39 reported on Friday. Of these, nine were Singaporeans, while seven were permanent residents, said MOH. This brings Singapore's total up to 60,943.

The number of new cases in the community has increased from four cases two weeks ago to 10 in the past week. The number of unlinked cases in the community in a week has also increased from three cases to five over the same period.

With 10 cases discharged on Friday, 60,598 patients have fully recovered from the disease. A total of 80 patients remain in hospital, including one in critical condition in the intensive care unit, while 220 are recuperating in community facilities.

Singapore has had 30 deaths from Covid-19 complications, while 15 who tested positive have died of other causes.