Blood clot case sparks vaccine alert
Healthcare workers are on alert for signs of a very rare blood clot among people given the AstraZeneca vaccine after Australia’s first probable case was admitted to hospital on Friday.
The state’s public health authorities are expecting to see a very small number of adverse reactions, as with any mass immunisation programme involving millions of people, the more likely being anaphylaxis.
The national medical regulator is investigating the case of a 44-year-old man hospitalised in Melbourne after developing a blood clot more than two weeks after his Covid-19 vaccination.
The case comes after several European countries paused their AstraZeneca rollouts following reports that 31 vaccinated people had developed cerebral venous sinus thrombosis among the millions who had received the AstraZeneca vaccine in Europe and the UK.
Deputy Chief Medical Officer Professor Michael Kidd said ‘‘one probable case of this clotting disorder has now been reported in Australia, and we are taking this very seriously’’.
A causal link between the man’s blood clot condition and the vaccine has not been confirmed.
Secretary of the Department of Health Dr Brendan Murphy said the man was in a stable condition and was not in intensive care. He said the risk of serious disease and death from Covid-19 was far greater than the risk of a very rare clotting disorder potentially associated with the vaccine.
‘‘We are talking about extremely rare events, perhaps one to two per million if you look at the UK, and the risk of dying of Covid is one to two per 100,’’ Murphy said.
‘‘We’re certainly taking this seriously, we’re working actively and the government will do at all times what the independent medical advice recommends.
‘‘If [Australian Technical Advisory Group on Immunisation] or TGA recommends a change we’ll act accordingly, but at the moment they’re not making that recommendation.’’
Kidd said anyone who received the AstraZeneca vaccine and experienced symptoms of a persistent headache or other worrying symptoms four to 20 days after the vaccine should seek medical advice as soon as possible.
NSW Health said there had been no cases of blood clots among people given the Covid-19 vaccines in the state.
The most likely adverse reaction is anaphylaxis soon after a vaccine is administered, which is why people are required to be monitored for at least 15 minutes after receiving a vaccine.
‘‘We are being open about possible risks and acknowledge the uncertainty that this will cause,’’ Kidd said.
Kidd directly addressed healthcare workers at a Friday afternoon press conference. He said the condition has presented as either a clot in the brain or thrombosis in other parts of the body and if healthcare workers noticed these warning signs in patients who had received the vaccine, they should refer them to an emergency department urgently.
The European Medicine Agency and the TGA previously conducted reviews of the available evidence and concluded the benefits of the vaccine outweighed the risks.
In a statement on Wednesday, the European agency said a causal link between the vaccine and the clots was not proven but is possible and analysis is continuing.
Associate professor Paul Griffin, director of infectious diseases at Mater Health in Queensland, said it was likely there was no connection between the man’s blood clot and the vaccine.
‘‘We obviously need to investigate carefully events when they do arise in temporal proximity to the vaccine, but on a whole, what we’re going to see is things that would have happened anyway occurring,’’ he said.
Griffin said about 10,000 clotting events occur each year in Australia, and he estimated people have about an eight per cent risk of having one in their lifetime.