An investigation is underway into the death of a 48-year-old woman in John Hunter Hospital, who received the AstraZeneca COVID-19 vaccine last week.

She suffered from underlying medical issues including diabetes and developed blood clots nearly a week after the jab.

Health authorities say it is unclear if her death was caused by a medical condition or the blood clots and any link to the vaccine is yet to be determined.

On Friday the 9th of April, the woman was assessed by her GP, who advised that the benefits of the vaccine outweighed the risks.

Although not a frontline worker, she was considered to be vulnerable, in the 1B category.

She received the vaccine from her GP the same day.

Yesterday she was admitted to hospital where she was rushed to the intensive care unit but passed away in the afternoon.

New South Wales Premier Gladys Berejiklian offered her condolences this morning on the Today show.

“We are waiting for the federal authorities to let us know whether there is a link and until that time I think we should just wait for that advice”, she said.

The federal government is no longer advising people under the age of 50 to get the AstraZeneca vaccine.