AstraZeneca COVID vaccine recipient admitted to hospital with blood clots2nd April 2021
“We are being open about possible risks and acknowledge the uncertainty that this will cause.
Professor Kidd 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.
The AstraZeneca COVID-19 vaccine and blood clots
- AstraZeneca is one of two coronavirus vaccines currently being administered in Australia. It’s likely most of the population will be given AstraZeneca over Pfizer, as Australia has ordered substantially more doses of it (53.8 million doses versus 10 million of Pfizer).
- AstraZeneca’s common side effects include: injection site tenderness (more than 60 per cent), injection site pain (more than 50 per cent), headache (more than 50 per cent), fatigue (more than 50 per cent), joint pain (more than 40 per cent) and chills (more than 30 per cent).
- Deputy Chief Medical Officer Michael Kidd says the side effects are expected, and are not of concern, unless the symptoms are severe or persistent.
- Several European countries paused their AstraZeneca rollouts after a handful of cases of blood clots emerged following vaccination. They have now restarted the programs after a review by the European Medicines Agency found the benefits of administering the vaccine continued to outweigh the risks.
- The European regulator concluded the number of people suffering blood clots after a dose of the vaccine was no higher than the rate you’d expect to see in the population.
- But this week, German officials decided to limit the use of AstraZeneca in people under 60 after more unusual blood clots were reported in a few people who received the shots. Europe’s drug regulator reiterated there was no evidence that would support restricting the use of the vaccine in any population. Investigations are continuing. Canada also recently halted the rollout for people aged under 55.
- In March, German and Norwegian research teams identified a possible mechanism – an autoimmune reaction – that could explain a link between the AstraZeneca vaccine and the rare clots.
- A Victorian man is in a Melbourne hospital with blood clots after receiving the AstraZeneca vaccine on March 22. It is not yet known if the blood clots are connected to the man’s vaccination. The case is being investigated by Australia’s medical regulator.
Professor Kidd chaired an Australian Health Protection Principal Committee meeting earlier on Friday afternoon and discussed advice from the Australian Technical Advisory Group on Immunisation and the TGA for health practitioners and those getting vaccinated.
“People who have received either of the COVID-19 vaccines should be aware of the common side effects, which include fever, sore muscles, tightness, and headaches,” he said.
“These symptoms usually start within 24 hours of receiving the vaccine, and they usually last for only one to two days. The side effects are expected, and are not of concern, unless the symptoms are severe or persistent.”
Professor Kidd said the side effects that concern health authorities were severe allergic reactions, which usually occurs shortly after vaccination and occurs with other vaccines.
“That is why people must be monitored for 15 minutes after vaccination,” Professor Kidd said.
“The reports from overseas of rare clotting disorders have occurred later than this, between four and 20 days after vaccination and have generally caused severe symptoms, requiring hospitalisation.”
The European Medicine Agency (EMA) and the TGA previously conducted reviews of the available evidence and concluded the benefits of the vaccine outweighed the risks.
The EMA’s safety committee met on March 31 to discuss its ongoing review of very rare cases of unusual blood clots associated with low numbers of platelets (thrombocytopenia) in people vaccinated with AstraZeneca’s COVID-19 vaccine.
Several European countries paused their AstraZeneca rollouts following report that 31 vaccinated people had developed cerebral venous sinus thrombosis. Most of the people affected were women under the age of 55.
On Wednesday, Germany suspended the vaccine’s use in people under the age of 60. Canada also recently halted the rollout for people aged under 55.
Australian regulators had also reviewed the preliminary data after the earlier reports of blood clotting.
That review did not identify any specific risk factors, such as age, gender or a previous medical history of clotting disorders, for these very rare events.
“A causal link with the vaccine is not proven, but is possible and further analysis is continuing,” the EMA said in a statement.
“Vaccinated people should be aware of the remote possibility of these very rare types of blood clots occurring. If they have symptoms suggestive of clotting problems as described in the product information, they should seek immediate medical attention and inform healthcare professionals of their recent vaccination,” the EMA said.
The European safety committee is due to provide its next update at a three-day meeting commencing on April 6.
In March, German and Norwegian research teams identified a possible mechanism – an autoimmune reaction – that could explain a link between the AstraZeneca vaccine and the rare clots.
Australia’s vaccine program is relying heavily on the AstraZeneca vaccine and there are plans to roll out more than 53 million doses this year.
Associate professor Paul Griffin, director of infectious diseases at Mater Health in Queensland, warned against assuming there was a link between the man’s blood clot and the AstraZeneca vaccine, saying it was likely there was no connection.
“We shouldn’t be concerned, what we need to be really careful of is observing events post vaccination and immediately assuming they’re related,” Professor Griffin said.
“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.”
Professor Griffin did not support pausing the AstraZeneca rollout in Australia at this point.
“When we do see these events reported we need to trust our regulator, whose role is to investigate these events,” he said.
“The TGA will not allow a vaccine to be used if there’s any increased risk of significant adverse events or death.”
Professor Griffin said about 10,000 thromboembolic events occur each year in Australia, and he estimated people have about an 8 per cent risk of having one in their lifetime.
What you need to know about possible side effects from vaccines
People who have received COVID-19 vaccines should be aware of common side effects, which include fever, sore muscles, tiredness and headache. These usually start within 24 hours of vaccination and last for 1-2 days.
These side effects are expected and are not of concern unless severe or persistent. Consumers should be particularly alert to severe, persistent headaches that are different to their “usual” pattern and do not settle with paracetamol or other painkillers.
If these symptoms occur consumers should seek medical advice as soon as possible.
Source: Australian Technical Advisory Group on Immunisation
“Because we are vaccinating such a large number of people in a short space of time, we will see thromboembolic events in people that have just recently been vaccinated, but that doesn’t mean it’s a causal association,” he said.
“By sheer coincidence, some of them will be potentially associated timing wise with the vaccine, but it is unlikely to actually be related in a causal sense.”
Infectious disease expert associate professor Linda Selvey said when thousands of people are being vaccinated in a short period “things can happen coincidentally”.
“Each potential adverse event is being investigated by experts who would take into account the risk factors for why that person might have had a blood clot … and the likelihood it happened by chance,” she said.
The public health physician said it was too soon to make a judgement on whether Australia should consider halting its use of AstraZeneca.
“More information is needed on the Victorian case to determine what caused the man’s blood clot,” she said.
“Without that it’s really hard to make a judgement. It also becomes hard to make a judgement until you’ve got strong population level data on the vaccine.”
She said it was worth remembering that in the UK, where masses of people had already received the AstraZeneca vaccine, there did not appear to be any increase in adverse blood clotting events.
In a statement in mid-March, the TGA said those reviews found the AstraZeneca vaccine was not associated with an increase in the overall risk of blood clots.
“The TGA continues to closely monitor the safety of the AstraZeneca COVID-19 vaccine and will work with AstraZeneca to update product information as required,” the TGA said at the time.
“If we detect a safety concern, we will take rapid action to address it and promptly provide information to the public.”
The ATAGI recommended – as a precaution – deferring vaccinating people who have a history of the rare blood clot disorders CVST and heparin-induced thrombocytopenia until further information from ongoing investigations in Europe is available.
Eastern Health, which oversees the hospital, declined to comment when contacted by The Age and The Sydney Morning Herald.
With Ashleigh McMillan
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Melissa Cunningham is The Age’s health reporter.
Rachel Clun is a federal political reporter at The Sydney Morning Herald and The Age, covering health.
Kate Aubusson is Health Editor of The Sydney Morning Herald.