SINGAPORE, April 19 — The sole community Covid-19 case registered in Singapore on Sunday (April 18) was confirmed to have the disease just two days after receiving his first dose of the coronavirus vaccine, the Ministry of Health (MOH) said.

The victim, a 39-year-old Indonesian man, has tested "preliminarily positive” for the B117 strain — a variant of the coronavirus that spreads faster than other versions but recent studies had found to be not as deadly.

"As the vaccine does not contain live virus, he could not have been infected due to vaccination,” MOH said. "It is possible for one to be infected just before or just after vaccination as it typically takes a few weeks for an individual to build up immunity after completing vaccination.”

MOH said the man, a sea crew on board a bunker tanker, has no links to previous cases. He had not disembarked from the vessel except to go for Covid-19 testing and vaccination.

The man had no symptoms and was detected when he was tested on April 15 as part of routine tests.

His pooled test result came back positive for Covid-19 the next day, and he was taken in an ambulance to the National Centre for Infectious Diseases.

An individual test done on April 16 also came back positive the following day.

The man had received his first dose of Covid-19 vaccine on April 15, MOH said.

All his close contacts, including crew members of the vessel, have been quarantined.

There were 22 other cases registered on Sunday, all of whom were imported and had already been isolated or placed on stay-home notice upon arrival in Singapore.

Among the 22: