Therapeutic Goods Administration head John Skerritt said investigations were underway after two men, 55 and 71, reportedly died from blood clots.
It is believed both received the AstraZeneca jab, which is recommended for use only in people over 50 because of extremely rare but serious blood clots.
Adjunct Professor Skerritt said the men had various blood clots but declined to provide more detail on privacy grounds.
He strongly cautioned the media and public against reaching any conclusion about the deaths and potential links to vaccination.
Darren ‘Misso’ Missen, 55, (pictured) died in hospital on April 21 from blood clots in his lungs eight days after receiving the vaccine
‘The current evidence does not suggest a likely association,’ he told reporters in Canberra on Thursday.
Darren ‘Misso’ Missen, 55, from Tamworth, died in hospital on April 21 from blood clots in his lungs eight days after receiving the vaccine.
Tributes have begun pouring in over social media for Mr Missen, who has been described by friends as a ‘top bloke’.
Friend Darren Craig said his ‘good mate’ was a ‘fit and healthy’ man but quickly deteriorated after being vaccinated.
‘I lost a good mate during the week … he was a fit healthy fella loved a schooner & a punt as we do,’ Mr Craig wrote on Facebook on Friday.
‘Darren had the corona Jab [sic] end of last week was a little bit off colour at work early this week and died from a blood clot in the heart Wednesday afternoon.’
A Sydney man, 71, also died days after getting the AstraZeneca Covid-19 vaccine. It is understood he had several underlying health conditions.
The TGA boss stressed the regulator was not seeing a flood of serious adverse reactions with just 11,000 reports from 2.1 million doses ranging from sore arms to heart attacks.
All serious incidents are carefully scrutinised with the rate of blood clots linked to AstraZeneca still around five in every one million shots.
Friends said Mr Messin was a ‘fit and healthy’ man prior to his death. Pictured: Tamworth Base Hospital
‘The benefits dramatically exceed the risks, so knowing there is a small background risk of clots is something not to hide,’ Professor Skerritt said.
‘But all medicines, all treatments, all procedures, driving a car, flying in a plane, have some risk and in the case of these vaccines the benefits outweigh the risks.’
Prime Minister Scott Morrison also urged caution about linking blood clot deaths to vaccines without proof from medical experts.
‘We’ve got to be careful about how we talk about these cases,’ he told Darwin radio Mix 104.9 on Thursday.
‘Let’s allow the medical facts to be established.’
The prime minister’s cautious tone comes as the government and health experts try to fight rising vaccine hesitancy.
Chief Nursing Officer Alison McMillan said stringent processes were in place to investigate adverse reactions.
‘It’s really important not to jump to conclusions here,’ she told the ABC.
The TGA has confirmed six cases of rare blood clots that are likely linked to the AstraZeneca vaccination.
A link between the vaccine and either death are yet to be established, but Therapeutic Goods Administration head John Skerritt said ‘current evidence evidence does not suggest a likely association’ (pictured, a Sydney nurse getting the jab)
Earlier this month, the federal government announced the Pfizer vaccine was the recommended shot for people under 50 after AstraZeneca COVID-19 was linked to rare blood-clotting condition thrombosis with thrombocytopenia syndrome (TTS).
There have been 1.1million doses of AstraZeneca administered in Australia as of April 22, and six reported cases of TTS.
Genene Norris, 48, from the New South Wales Central Coast died on April 14 after receiving the AstraZeneca jab on April 8.
Ms Norris, a diabetic, developed blood clots the next day and was later placed on dialysis in an intensive care unit until her death.
The Therapeutic Goods Administration’s vaccine safety investigation found Ms Norris’ case of thrombosis was likely linked to the AstraZeneca vaccine.
The first two cases – a Western Australian woman and a Melbourne man, both in their 40s – are still in hospital but are recovering well.
Last week, three more Australians were diagnosed with the rare blood clotting disorder.
‘The VSIG (Vaccine Safety Investigation Group) concluded that all three of the cases were likely linked to vaccination,’ the TGA said on Friday.
‘All three patients are clinically stable, have responded well to treatment and are recovering.’
On April 21, a Queensland Police officer, 40, who worked patrolling the state’s quarantine hotels was hospitalised with blood clots after receiving the Pfizer vaccine.
Health authorities are yet to determine whether it was linked to the jab and the case is currently being investigated by the Queensland Health and the Therapeutic Goods Administration.