Health officials said on Saturday that uninfected individuals aged 18 to 59 who are at higher risk of coronavirus exposure or need a Covid jab for other reasons - such as overseas study - can have a fourth vaccine from now on - regardless of whether their previous doses were BioNTech or Sinovac.

They said the online booking system is currently being updated, so from Saturday until Wednesday, people eligible for a fourth jab can go to Community Vaccination Centres - except those located at private hospitals and the Satellite Community Vaccination Centre at the Leighton Centre - or Hospital Covid-19 Vaccination Stations to get a same-day ticket for vaccination.

They said that from 8am on Wednesday, members of the public will be able to book a fourth dose online.

Officials said that people between 18 and 59 choosing a fourth jab may opt to get it at least six months after their third vaccination.

The announcement comes a day after experts advising the government on the pandemic recommended that people between 18 and 59 consider a fourth jab if they've never been infected.

The advisers said that although three doses of BioNTech or Sinovac are highly effective in warding off serious illnesses or death, the level of protection wanes after several months.

People who are aged 60 or above are already recommended to get a fourth shot.