The first batch of volunteers aged between 21 and 55 in Singapore have received a dose of a potential coronavirus vaccine being developed in the country.

Called Lunar-Cov19, the vaccine is developed by Duke-NUS Medical School and American pharmaceutical company Arcturus Therapeutics.

Arcturus in a statement on Tuesday said that this first phase of the trial involved volunteers aged between 21 and 55, who were injected with a single shot of the vaccine.

Data from this phase of the early-stage trial would be used to select the dosage regimens of the next phase, which will involve those aged 56 to 80, as well as younger adults.

Arcturus president and chief executive Joseph Payne said that based on pre-clinical trials, its vaccine may only need to be administered once, and at a very low dose.

"These favourable attributes could greatly facilitate mass vaccination campaigns necessary to control this global pandemic," he said.

As of last week, more than 250 people here had volunteered for the trials of the vaccine but only around 100 were selected.

The trial, which is being administered by the SingHealth Investigational Medicine Unit, is expected to last until October this year.

The vaccine was originally slated to begin trials in September, but had been approved ahead of time due to pre-clinical trials "exceeding expectations".

Lunar-Cov19 contains genetic material called mRNA, which encodes part of the virus. Injected into a person, it causes the body's cells to begin manufacturing a protein similar to that of the virus, allowing the body to recognise and learn to fight it.

Meanwhile, Singapore on Thursday reported 102 new coronavirus cases, taking the national tally to 55,497.

Migrant workers living in dormitories made up the majority of the cases, said Ministry of Health (MOH) in its daily update.

The new cases included five community cases comprising a permanent resident and four work pass holders.

There were also six imported cases who had been placed on stay-home notices upon arrival in Singapore.

On Wednesday, 800 foreign workers were quarantined after health authorities discovered a case among them in a dormitory that had been cleared of the virus.

They are among about 22,800 workers who are still serving out their quarantine period. These workers will be tested when their quarantine ends, and it expects the new infection case counts to remain high in the coming days before tapering off, said MOH.

The 11 imported patients reported on Wednesday comprised two Singaporeans, three work pass holders, one work permit holder, four dependant's pass holders and one special pass holder.

These patients had returned from Indonesia, India and the Philippines.

Among them is a Filipino seaman holding a special pass who arrived from India on August 8 on a vessel.

The seaman reported symptoms and was tested on the vessel. He remained on the vessel until his test result came back positive for COVID-19, and was subsequently conveyed in an ambulance to a hospital.

Singapore has recorded 27 deaths from COVID-19 complications, while 15 who tested positive have died of other causes.