No evidence that vaccines can directly cause heart attacks and strokes: HSA

HSA said that no deaths from heart attacks, strokes or any other causes suspected to be associated with the vaccines have been reported locally. ST PHOTO: ALPHONSUS CHERN

SINGAPORE - There has been no uptick in heart attacks or strokes among vaccinated people, and no evidence that the Covid-19 vaccines used here can directly cause them, the Health Sciences Authority (HSA) said on Thursday (May 6).

"A greater frequency of heart attacks and strokes has not been observed in vaccinated persons locally and to date, there is also no evidence that the vaccines can directly cause these events," HSA said in its first update on the safety of the mRNA vaccines used here. Only the Pfizer-BioNTech and Moderna vaccines are used here.

"No deaths from heart attacks, strokes or any other causes suspected to be associated with the vaccines have been reported locally," HSA said.

It had looked at the cases of adverse events - there were 2,796 - that arose from the more than 2.2 million doses administered between Dec 30 and April 18.

Due to the large number of people being vaccinated, some may, by chance, experience medical events such as heart attacks and strokes in the days or weeks after vaccination. And this may not be related to the vaccination, said HSA.

At a Ministry of Health (MOH) media briefing on Thursday (May 6), an HSA spokesman said it is hard to ascribe causality to heart attacks or strokes as they can happen spontaneously and generally these patients do have underlying medical conditions.

Professor Teo Yik Ying, dean of the National University of Singapore's Saw Swee Hock School of Public Health, said at the briefing that typically, in a three-month period, there would be some 2,000 stroke cases and slightly fewer than 3,000 heart attack cases. People can experience these, whether they are vaccinated or not.

"There have not been any established links between cases of stroke or heart attack with either the Pfizer or Moderna vaccines in the United States, which has seen at least 240 million doses delivered as at May 5," he said.

He said vaccination remains key to the battle against Covid-19 as new variants spread and form clusters here. "The signal from the Tan Tock Seng Hospital (TTSH) cluster is that vaccination helps because it provides much better protection against serious outcomes of infection," he said.

MOH's director of medical services Kenneth Mak had earlier said that eight patients in the TTSH cluster who had been vaccinated were either asymptomatic or exhibited very mild symptoms, and none required oxygen therapy.

"Of those not protected by vaccination, seven of the 20 had need of oxygen therapy," he had said at a May 4 Covid-19 press conference.

MOH said on Thursday it had received and was processing applications for the Vaccine Injury Financial Assistance Programme for Covid-19 vaccination (Vifap).

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Under Vifap, which was launched on March 17, those who need inpatient treatment and medical intervention, and who subsequently recover, will get $2,000.

Those who require admission to high dependency or intensive care wards, and subsequently recover, will get $10,000.

Those who die or suffer permanent severe disability as a result of the vaccination will get $225,000.

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