The Therapeutic Goods Administration has been notified of two more fatal cases of the rare blood clotting disorder related to AstraZeneca.
One is a 44-year-old man from Tasmania, and the other a 48-year-old woman from Victoria, reported as a probable thrombosis with thrombocytopenia syndrome (TTS) case last week.
Tasmanian State Health Commander Kathrine Morgan-Wicks said the man was a confirmed case of TTS.
He was vaccinated in a Tasmanian state vaccination clinic.
Ms Morgan-Wicks said TTS was a rare but serious condition.
"TTS is thought to occur due to an immune response to the AstraZeneca vaccine and is different to other conditions," she said.
She said people should seek immediate medical attention if they developed symptoms such as "severe or persistent headaches, blurred vision, confusion or seizures, shortness of breath, chest pain, leg swelling or persistent abdominal pain".
Ms Morgan-Wicks said in people over the age of 60 the benefits of the AstraZeneca vaccine outweigh the rare risks associated with vaccination.
The man's death will be investigated by the coroner.
Victorian Acting Chief Health Officer Ben Cowie said every loss of life was tragic.
"It is one-in-a-million," he said.
"One is too many, but what we are trying to achieve is a balance between that rare but serious side effect and the absolute fundamental good that is vaccinating our community against COVID-19."
Victoria today recorded 26 new local COVID-19 cases.
Two of the new cases were in the community while infectious, but the rest were in quarantine.
It brings the number of cases in the state's outbreak to 133.
6.1m doses of AstraZeneca vaccine administered
There have been 6.1 million doses of the AstraZeneca vaccine administered, and six deaths related to the first dose, the TGA has said.
There have been 87 cases of TTS to date.
Of the four previous deaths, three were cases of TTS and one was a case of immune thrombocytopenia (ITP).
The Australian Technical Advisory Group on Immunisation (ATAGI) recommends the Pfizer vaccine as preferred for those aged 16 to 60.
In June, Prime Minister Scott Morrison announced anyone under the age of 40 could approach their GP to request the AstraZeneca vaccine.
The next day, ATAGI's co-chair Christopher Blyth poured water on the suggestions, saying under 40s should only be considering getting AstraZeneca in "pressing circumstances".
Prime Minister Scott Morrison today said he was "sorry" for the challenges his government had with rolling out the COVID-19 vaccine earlier in the year.
The Prime Minister has been facing growing pressure to acknowledge failures in the program following several outbreaks of the Delta strain of COVID-19.
Tasmania's Director of Public Health Mark Veitch said the incidence of TTS after AstraZeneca was now estimated to be about 2 in 100,000.
"People in this gentleman's age group had been advised to weigh up the risks benefits [of the AstraZeneca vaccine] carefully for several months certainly before this vaccine was provided," he said.
"The public does need to know that there are side effects but they also need to know there are benefits from vaccines."
[Click through to send us your questions about COVID-19]