No increased stroke risk from bivalent vaccine: MOH

The safety profile of the bivalent mRNA vaccines has been observed to be similar to that of their monovalent versions. PHOTO: REUTERS

SINGAPORE - Local data does not currently show an increased risk of ischaemic stroke after receiving either the Moderna or the Pfizer-BioNTech bivalent Covid-19 vaccines, the Ministry of Health said on Saturday.

“The safety profile of the bivalent mRNA vaccines has been observed to be similar to that of their monovalent versions,” the ministry said in response to media queries.

This comes after data from Vaccine Safety Datalink, under the United States Centres for Disease Control and Prevention (CDC), suggested that those aged 65 and above may have an increased risk of an ischaemic stroke – which can interrupt blood supply to the brain – within 21 days of receiving a shot of the Pfizer-BioNTech bivalent vaccine.

However, the US CDC as well as the Food and Drug Administration said the data suggests that it is “very unlikely” that there is a genuine clinical risk.

MOH noted the risk was seen in one vaccine safety monitoring system, but not observed and validated in other US safety systems or analyses, or those of other countries.

It added that the US has also not changed its recommendation that people receive the bivalent mRNA vaccines as boosters.

“Pfizer and BioNTech have also stated in a statement that compared to published incidence rates of ischaemic stroke in this older population, they have to date observed a lower number of reported ischaemic strokes following vaccination with the bivalent vaccine,” the ministry said.

MOH stressed the importance for people to keep up-to-date with their Covid-19 vaccinations, noting multiple international studies showed receiving an updated bivalent Covid-19 vaccine reduces the risk of severe disease and death.

“The Health Sciences Authority and Expert Committee on Covid-19 Vaccination assess that the benefit of both the Moderna and Pfizer-BioNTech/Comirnaty Covid-19 bivalent vaccines continue to outweigh the risks,” it said, adding that the expert committee continues to recommend that individuals receive their bivalent booster doses.

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