The TGA has announced a second case of thrombosis with thrombocytopenia likely to be associated with the AstraZeneca COVID-19 vaccine
It issued a statement saying that the Vaccine Safety Investigation Group, its panel of expert advisors, met on Monday evening, where it concluded that a recently reported case of thrombosis with thrombocytopenia is likely to be linked to vaccination.
“This is the second Australian report of a case of thrombosis with thrombocytopenia following the AstraZeneca COVID-19 vaccine,” it said.
“The case occurred in a woman in her 40s who was vaccinated in Western Australia. The person remains in hospital receiving treatment and is in a stable condition.”
The TGA says that the VSIG meeting reviewed the case in detail, and assessed the case using the WHO’s causality assessment tool to rate the level of certainty of a link between the event and the vaccination.
The panel included medical experts in vaccine safety, infectious diseases, haematology, immunology, neurology, public health and vaccine confidence, and a consumer representative.
The panel concluded that the case is similar to cases seen in Europe and the United Kingdom of the rare clotting disorder, referred to as “thrombosis with thrombocytopenia syndrome,” because it included significant venous thrombosis, thrombocytopenia and blood test results consistent with other cases of TTS (notably, elevated D-dimer and antibodies to platelet factor 4).
Diagnosis was complicated by some ambiguous imaging findings and the need to run additional confirmatory blood tests.
In making the announcement, the TGA noted there have been about 700,000 doses of AstraZeneca COVID-19 vaccine administered in Australia to date, so while numbers are small, two cases of the thrombosis with thrombocytopenia syndrome equates to a frequency of one in 350,000.
The UK regulator, the Medicines and healthcare products Regulatory Agency, has concluded from its review of cases reported in the UK that the overall risk of these rare blood clots was approximately one in 250,000 who receive the vaccine.
The TGA says it is carefully reviewing all Australian reports of blood clots following the AstraZeneca vaccine, and are requesting further information from reporters where needed, to identify any further possible cases of TTS to better characterise this potential risk.
People who have received COVID-19 vaccines should be aware of the common side effects, which include fever, sore muscles, tiredness and headache.
These usually start within 24 hours of vaccination and last for one to two days.
“These side effects are expected and are not of concern unless severe or persistent,” it said.
“The reports of these rare clotting complications have occurred later (between day four and 20 after vaccination) and have generally been severe, requiring hospitalisation.”
Patients should seek immediate medical attention if, a few days after vaccination, they develop symptoms such:
- as a severe or persistent headache or blurred vision;
- shortness of breath, chest pain, leg swelling or persistent abdominal pain; and/or
- unusual skin bruising and/or pinpoint round spots beyond the site of injection.
The TGA says it encourages health professionals and consumers to report suspected side effects following immunisation with COVID-19 vaccines.
A spokesperson for AstraZeneca told the AJP that it, “is aware that a case of thrombosis with thrombocytopaenia has been reported in a woman who recently received the AstraZeneca COVID-19 vaccine”.
“We are pleased to hear that she is in a stable condition, and is receiving treatment in hospital,” the spokesperson said.
“Patient safety remains AstraZeneca’s highest priority and we continue to support regulators in Australia and overseas.
“Tens of millions of people have now received our vaccine across the globe. The extensive body of data from two large clinical datasets and real-world evidence demonstrate its effectiveness, reaffirming the role the vaccine can play during this public health crisis.
“Our global commitment remains to play an important role in addressing the current global health emergency posed by COVID-19 by providing a safe and effective vaccine, at no profit during the pandemic.”
Australian Government Chief Medical officer, Professor Paul Kelly, said in a statement to the general public on Tuesday that the Government’s decision would have “implications” for the vaccine rollout program.
“The Australian Government will work through these implications with the states and territories as an urgent priority,” he said.
He stressed the fact that “for our Australians aged 50 and over, it is very important they know the AstraZeneca vaccine is highly effective at preventing death and severe illness among people who have contracted COVID-19 – and that the incidence of the blood-clotting syndrome is very rare”.
He also stressed the risk to Australians from COVID-19 itself.
“My unequivocal advice to Australians remains that when your time comes to get vaccinated – take the vaccine you are offered,” he said.
“It is safe and effective. The risk of a severe side effect will be very small.”