SINGAPORE - About 1 per cent of people who turned up for their Covid-19 vaccinations were rejected due to concerns about allergies and conditions that could make them ineligible to receive the jab.

Additionally, close to 98 per cent of those who booked appointments for vaccinations in the last 30 days showed up - meaning about 2 per cent of them did not show up for their appointments.

These figures were revealed by Senior Minister of State for Health Janil Puthucheary in Parliament on Monday (April 5), in response to a question from Workers' Party chairman Sylvia Lim (Aljunied GRC) on the proportion of people who have been rejected for the vaccine.

Ms Lim also asked about plans to minimise the wastage of vaccines.

In response, Dr Janil said there is no vaccine wastage as a result of people who do not turn up for their vaccinations or those who were unable to get their jabs due to concerns over issues like allergies.

"We closely monitor the appointment bookings and historical take-up rate, and deliver the appropriate number of vaccine doses to the vaccination sites," he said.

Unopened vials can be stored at the vaccination sites for at least three days, and to avoid vaccine wastage, staff giving the jabs will start a new vial only when they have checked that there are individuals awaiting vaccination.

There are also pre-planned lists of individuals who will be invited for vaccination at the end of the day to use any balance remaining in a multi-dose vial and further minimise wastage, Dr Janil said.

They could be staff who are working at the vaccination sites or front-line volunteers who have an active role in engaging seniors on the shots.

"We encourage everyone to be vaccinated when your turn comes, and to turn up at the vaccination appointments that you have made so that you do not deny another person of the opportunity," he added.

Ms Foo Mee Har (West Coast GRC) asked if a system can be arranged so that others who are not yet eligible to take the vaccine can be on standby at the vaccination centres to take the jab, if there are doses left over at the end of the day even after catering to those on the pre-planned list.

Dr Janil said the MOH will study her suggestion, and added that the ministry is continuing to study how best to deal with the challenges of prioritising those most at risk in the vaccine roll-out while ensuring some equitable distribution across the population, as well as helping those who have some urgent needs to be vaccinated.

Responding to Ms Lim on whether MOH has eased its Covid-19 vaccination guidelines, he confirmed the ministry has updated its advice on eligibility for the jab.

"As an increasing number of people have been vaccinated, we have confidence over the situations in which someone previously thought to be ineligible might now go forward and have the vaccine," he said, adding that the online systems and MOH's guidance to staff manning counters and hotlines on the vaccine have also been updated.

He stressed that individuals deemed ineligible for the vaccine now may still be able to take the jab at a later stage.

"This is about deferring the appointment and the consultation to a time where perhaps they might subsequently become eligible, and we will continue to pay close attention to this segment of the population."

In response to Mr Lim Biow Chuan (Mountbatten), who asked if Singaporeans can opt in to receive early vaccinations if they need to travel for work and studies, Dr Janil said an appeals channel has been opened since March 16 for Singapore citizens and permanent residents who need to travel overseas on compassionate grounds, or for employment or study purposes.

"We will prioritise appeals with earlier travel dates if they are able to complete the two-dose regimen prior to departure," he said.

The Ministry of Health (MOH) will be conducting further studies to monitor and review the extent and duration of immunity provided by the Covid-19 vaccines, said Dr Janil.

This includes collecting selected post-vaccination samples from groups such as healthcare workers, front-line staff and seniors to monitor the persistence of antibodies for up to 24 months.

In line with international practices, there are no plans to test the serology of everyone who is vaccinated in Singapore, he said in response to Mr Murali Pillai (Bukit Batok), who asked if MOH intends to measure the antibody levels of people over time after they have been jabbed to assess if they retain immunity against the virus.

More details about the studies will be shared once they have been completed, he added.