SINGAPORE - The Health Sciences Authority (HSA) has granted interim authorisation for Pfizer-BioNTech’s bivalent Covid-19 vaccine for people aged 12 and above.

The bivalent vaccine can be used as a booster jab for those who have received their primary series vaccination. It targets both the original strain of the coronavirus and the Omicron BA.4 and BA.5 variants.

The Expert Committee on Covid-19 Vaccination and Ministry of Health (MOH) will issue official recommendations on the use of the vaccine when ready, said HSA in its statement on Tuesday.

Although clinical studies for the latest bivalent Cominarty vaccine are still under way, HSA said a previous study – for the bivalent Pfizer-BioNTech vaccine that protects against the original strain as well as the BA.1/2 variants – showed promising results.

In that study, the bivalent vaccine was shown to elicit a stronger immune response against the Omicron BA.1 variant, while still being effective against the original Covid-19 strain.

HSA said it used this previous study as the primary basis for granting approval, as Omicron sub-variants are closely related to one another.

Under the Pandemic Special Access Route (PSAR), HSA is allowed to start evaluating new vaccines, medicines and medical devices from the early stages of clinical studies, instead of waiting for full data sets to be submitted.

As a condition for the interim authorisation under PSAR, Pfizer and BioNTech are required to submit data from their ongoing clinical study to ensure that the vaccine’s benefits continue to outweigh the risks, said HSA.

In their ongoing Phase 2/3 clinical study for the latest bivalent vaccine, a preliminary analysis of 80 participants aged 18 and above showed higher immune responses against the Omicron BA.4 and BA.5 sub-variants as well, said HSA. The authority added that the safety of the bivalent jab was comparable to that of the original vaccine.

Those who have taken it would possibly experience pain and tenderness at the injection site, fatigue, headaches and muscle pain – all of which were side effects associated with the original vaccine, and would typically clear up in a few days.

Health Minister Ong Ye Kung said in Parliament last Thursday that the vaccine will be made available by the end of this year.

Singapore has already approved the bivalent version of Moderna’s Spikevax vaccine, which was introduced at nine joint testing and vaccination centres on Oct 14.

The jab is available to those who have yet to receive minimum protection, or the equivalent of three mRNA doses, as well as those aged 50 and above and whose last Covid-19 vaccine jab was at least five months ago.