On Apr. 11, the sole locally-transmitted Covid-19 had already received two doses of the vaccine.
The Work Permit holder was employed by Seafront Support Company Pte Ltd.
He resides in a dormitory located at Brani Terminal Avenue. He is asymptomatic and was detected when he was tested on Apr. 7 as part of Rostered Routine Testing (RRT) of port workers.
His earlier tests from RRT, the last being on Mar. 24, were all negative for Covid-19.
His serology test came back positive though MOH has assessed that this is likely a current infection.
Worker's close contacts tested negative
In an update on Apr. 14, Minister for Transport Ong Ye Kung provided more details on the case.
He shared that the worker's job as lashing specialist involves going onboard ships to secure and unsecure containers. They do not interact with the ship's crew.
The worker received his first dose of Covid-19 vaccine on Jan. 25 and the second dose on Feb. 17.
MOH previously said that this likely accounts for his lack of symptoms and the positive serology test as he has produced antibodies following the vaccination.
Thus far, it appears that the worker has not transmitted the virus to anyone else.
156 of the worker's close contacts were quarantined, and all have tested negative so far. They will be tested again before they are discharged from quarantine.
Over 1,500 other workers living in the dormitory have also tested negative for Covid-19.
Vaccine effective in protecting individuals
Ong also said the case had reinforced their understanding of the virus and vaccinations.
Firstly, that it is possible for vaccinated individuals to be infected.
Secondly, that the vaccine significantly reduces the likelihood of the virus being transmitted between people, and that vaccines are effective in protecting individuals from more severe forms of Covid-19.
Associate Professor Hsu Li Yang, Infectious Diseases Programme Leader at the National University of Singapore’s Saw Swee Hock School of Public Health told CNA that prevention of symptomatic Covid-19 occurred for approximately 94 to 95 per cent of participants in the clinical trials.
Meanwhile, "real world" experience in the U.S. and Israel shows that the efficacy of vaccines are less than 90 per cent, Hsu said.
This means that around one in 20 people on average can develop Covid-19 if exposed to the virus, CNA reported.
However, chances of this happening in Singapore are "very low" as the spread of the virus in the community here is minimal.
Vaccination efforts in Singapore are currently well under way, and Singaporeans can now choose the type of vaccine they want, by choosing which vaccination centre or polyclinic they wish to go to.
Related stories
Top photo from Ong Ye Kung / FB