Three more blood-clotting cases most likely linked to AstraZeneca vaccine

Federal health authorities have concluded that three more cases of a rare blood clotting disorder are most likely linked to the AstraZeneca COVID-19 vaccine.

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Vials labelled with partially torn sticker “AstraZeneca COVID-19 Coronavirus Vaccine” are seen in front of a displayed AstraZeneca logo in this illustration taken March 15, 2021. REUTERS/Dado Ruvic/Illustration

The Therapeutic Goods Administration said it had reviewed suspected thrombosis with thrombocytopenia syndrome (TTS) in an 80-year-old Victorian man, a 35-year-old NSW woman and a 49-year-old Queensland man.

The 80-year-old man is the first Australian case reported in a patient older than 50.

“The Vaccine Safety Investigation Group [VSIG] concluded that all three of the cases were likely linked to vaccination,” the TGA said in a statement.

“All three patients are clinically stable, have responded well to treatment and are recovering.”

The federal government updated its advice on April 8 to make the Pfizer vaccine the preferred jab for Australians under 50.

There have now been six cases most likely linked to the AstraZeneca vaccine, including one linked to the death of 48-year-old Genene Norris from the NSW Central Coast.

While the cases met the international criteria for the syndrome, two of the three appeared to be milder forms.

In one of the new cases, the patient developed symptoms “unusually late”, 26 days after vaccination.

The six reported cases developed symptoms between four and 26 days after vaccination.

“The VSIG concluded that the events were TTS, very likely linked to vaccination because of the consistency of the cases with the current working case definition for TTS, and the absence of known alternative risk factors and causes for the events,” the TGA said.

“However, further follow-up of some remaining details, including information about the patients’ medical histories, and some imaging and blood test results, is still being completed.”

One of the new cases had a blood clot in one of the sinuses in the brain, presenting as a headache, nosebleed, nausea and vomiting.

The other two cases involved more common sites for blood clots: in one case a deep vein thrombosis in the calf, which presented as leg pain nine days after vaccination, and in the other a deep vein thrombosis in the upper leg.

To date, about 1.1 million doses of the AstraZeneca vaccine have been administered in Australia.

“The overall number of reports received for blood clots following vaccination so far has been no higher than the expected background rate for the more common type of blood clots in Australia,” the TGA said.

“These can occur in around 50 Australians every day separate to vaccination and are not related to the rare TTS clotting disorder.”

No cases of TTS associated with the Pfizer vaccine have been detected in Australia.