A coroner's autopsy has shown that a 72-year-old woman, who died a day after her first dose of a Covid-19 vaccine, did not show any allergic reaction to the jab.

Instead, the woman, who had blocked blood vessels, had died of a heart attack, the Ministry of Health (MOH) said yesterday.

It was responding to questions that the woman's son, Mr Andrew Tan, had posted on Facebook.

Madam Doreen Chan had her first dose of the Pfizer-BioNTech vaccine on June 3, and "everything seemed fine except for a sore arm", said Mr Tan, chief executive of local diaper company Pee-Ka-Poo. She collapsed on June 4 at around 7.15pm and was taken by ambulance to Sengkang General Hospital, where she died at around 9pm.

MOH said that Madam Chan had been assessed by trained healthcare workers to be suitable for Covid-19 vaccination, and had been observed for about 30 minutes after she received the jab, in line with vaccination protocols.

"The case was referred to the coroner who conducted an autopsy and determined that the cause of death was ischaemic heart disease. This is the term given to heart problems caused by narrowed heart arteries," MOH said.

"The autopsy found longstanding blockage of the blood vessels supplying blood to the heart muscles, which could not be caused by vaccination. There were also no indications of an allergic reaction to the vaccines."

The ministry added that "the coroner is legally separate from and independent of the Ministry of Health, and determines the definitive cause of death".

Sengkang General Hospital said that it has contacted Madam Chan's family and will be providing more details about its findings on what happened.

Tham Yuen-C