SINGAPORE - From Oct 4, people aged between 50 and 59 will be invited to take their Covid-19 vaccine booster shots.

They will join those aged 60 and above and residents of aged-care facilities, who started their booster regime from Sept 15.

In a statement on Friday (Sept 24), the Ministry of Health (MOH) said that adults aged 50 to 59 have a higher risk of underlying comorbidities, which is the simultaneous presence of two or more diseases or medical conditions. Thus, they have a risk of severe illness as compared with younger people.

"Many would have completed the full regimen of their primary course of vaccination earlier in the year, their levels of protection could have decreased over time," said the ministry. "Boosting the immunity of members of our population will ensure continued high levels of protection against severe disease."

The Expert Committee on Covid-19 Vaccination (EC19V) has recommended that adults aged 50 to 59 years receive an additional mRNA shot of the Pfizer or Moderna vaccine at least six months after their two-dose vaccine regimen.

A booster dose will ensure that a high level of protection from severe disease is maintained across a longer period.

As at Thursday (Sept 23), almost 91,500 seniors aged 60 and above have received their booster dose, and around 56 per cent of seniors have either booked an appointment or already received their booster dose.

For those who have been invited to take their booster shots, an SMS with a personalised booking link will be sent to the mobile number that they had registered with for their first two doses, for them to book a new appointment at this website.

These individuals may receive their booster dose at any vaccination centre, polyclinic, or participating Public Health Preparedness Clinics (PHPC) islandwide.

At the multi-ministry task force press conference tackling Covid-19 on Friday, Health Minister Ong Ye Kung said: "By the end of today, we would have invited about 605,000 seniors above the age of 60 to book their appointments. The uptake has been good and encouraging. For example, in the first batch of invitations we sent out... 70 per cent have taken their injections or booked their appointments.

"Across all the batches of appointments, over half have done so (taken injections or booked appointments) as the numbers are rising," he added.

Mr Ong also said that the extension of the booster programme will add a further layer of protection for the seniors, and it is part of a slew of measures to cope with the rise in daily cases, which may eventually reach up to 2,000 or 2,500 cases a day.

The EC19V has also reviewed the dosing for the Moderna vaccine used for boosting and recommended that 50 micrograms (mcg) - or half of the usual dosage for the first two shots - is sufficient to boost immune response.

To ensure the efficient use of vaccines, vaccination sites carrying the Moderna vaccine will begin administering the vaccine at a dosage of 50mcg for booster doses from Saturday (Sept 25), said the MOH.

The ministry also assured the public that there will be no safety issues for those who had taken 100mcg of the Moderna vaccine for their booster dose.

The 100mcg dose will continue to be used for the first two doses and for immunocompromised people requiring a third shot to boost their immunity.

Immunocompromised people include transplant patients on medications that suppress the immune system, cancer patients on active treatment with chemotherapy, and people who have advanced or untreated HIV.

There will be no change in the 30mcg dosage for the Pfizer-BioNTech/Comirnaty vaccine for all three shots.

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