SINGAPORE - People aged 60 and older, as well as those who are medically vulnerable, who have not received the updated bivalent vaccine booster are advised to do so about a year after their last booster shot.

They can start getting the booster jab five months or more after their last dose.

Those who have not completed the doses needed for minimum protection are urged to do so as soon as they can, said the Expert Committee on Covid-19 Vaccination.

In a statement on Monday, the committee said there has been a surge in Covid-19 cases in recent weeks, which has resulted in more hospitalisations. It added that hospitalised Covid-19 patients were more likely to have not been up to date with their Covid-19 vaccinations and not received their bivalent vaccine dose.

A substantial number of those hospitalised with Covid-19 had not received vaccinations for minimum protection, said the committee.

To ensure minimum protection, the committee recommends that adults receive at least either three doses of the mRNA vaccines or Novavax, or four doses of the Sinovac-CoronaVac jab.

There has been an increase in the number of people hospitalised due to Covid-19 between Feb 26 and May 13, according to data published on the Ministry of Health website.

Most of the cases are people aged 60 and older.

Between May 7 and 13, there were about 336 people hospitalised daily on average, of which about 285 were aged 60 and older.

In comparison, an average of about 44 people were hospitalised daily during the period between Feb 26 and March 4, of which about 35 people were aged 60 and older.

Given that the surge in Covid-19 cases is due to the Omicron variants, the bivalent vaccine boosters provide better protection against the variants circulating in Singapore and overseas, said the Expert Committee.

It said: “Vaccination is essential to achieve a good level of protection against Covid-19 severe disease, especially among seniors aged 60 years and above who are significantly more likely to require medical care and hospital admission should they fall ill with Covid-19.

“The Expert Committee continues to urge every senior and medically vulnerable person to have minimum protection at the very least, and achieve optimal protection by being updated with the bivalent vaccines.”

More than 17 million doses of Covid-19 vaccines have been administered in Singapore, and more than 13 billion doses have been administered around the world, the committee said.

The benefits of Covid-19 vaccination far outweigh the risks, it added.

The risk of serious side effects from Covid-19 vaccinations, the committee said, is about seven in 100,000 persons in Singapore, and the numbers are lower with bivalent mRNA boosters.

The Expert Committee said: “In contrast, the risks of severe illness from Covid-19, including breathing difficulties and even death, can be as high as around seven in 100 persons among unvaccinated seniors.

“Even among unvaccinated adults aged younger than 60 years, the risk of severe Covid-19 can be two in 1,000. Vaccination reduces the risk of severe illness by more than 80 per cent.”

On Monday, Prime Minister Lee Hsien Loong said in a Facebook post that he had tested positive for Covid-19 – his first time contracting the disease since the pandemic began.

Mr Lee, who is 71, said he is “generally feeling okay”. He added that he was advised by doctors to self-isolate until he is asymptomatic.

He received his most recent Covid-19 booster jab last November, he said.