SINGAPORE - About 31,500 people aged 18 and above who are eligible for Covid-19 booster vaccination have yet to make their appointments as at Monday (Feb 7).

From Feb 14, they will no longer be considered fully vaccinated, the Ministry of Health (MOH) said in a statement on Tuesday (Feb 8).

Instead, their vaccination status will change to "additional dose needed".

These people had taken the last dose of their primary series - such as the Pfizer-BioNTech/Comirnaty or Moderna vaccine under the national vaccination programme - more than 270 days ago.

The vaccination status change will also apply to those who received three doses of the Sinovac-CoronaVac or Sinopharm vaccine, as well as regimens of other World Health Organisation Emergency Use Listing vaccines. These include those who have received one dose of the Johnson & Johnson vaccine, or two doses of the AstraZeneca, Covishield, Covaxin or Novavax vaccines.

The ministry said it has been progressively sending out SMS reminders to these people.

"We strongly urge these individuals to make their appointments or walk in to any of the vaccination centres for their booster dose as soon as possible," MOH added.

Walk-ins to vaccination centres are available from Mondays to Thursdays before 7pm.

The list of vaccination centres can be found at this website.

Those who are medically ineligible for mRNA vaccines may consider taking the Sinovac-CoronaVac vaccine as a booster vaccine, MOH said. Otherwise, it is not recommended as a booster vaccine.

Those who are unsure if they require a booster vaccine can go to MOH's online calculator at this website to check if they are required to receive a booster shot.