Since last week’s report, a further six reports of blood clots and low blood platelets have been assessed as TTS and considered likely to be linked to the AstraZeneca vaccine. Three are newly reported confirmed cases: one in a 57-year-old woman from Victoria, one in a 53-year-old man from South Australia and the final case in an 18-year-old woman in Queensland. Review of an earlier case in a 79-year-old Victorian man has now been confirmed as meeting the diagnostic criteria. Two other new cases, in an 87-year-old woman from South Australia and a 71-year-old woman from Victoria, were deemed probably related to the vaccine, but more clinical information is required for any confirmations to be made.
The 18-year-old was vaccinated prior to the 8 April 2021 recommendation by Atagi [the Australian technical advisory group on immunisation] that Comirnaty [Pfizer] is preferred over the AstraZeneca vaccine in adults aged under 50 years. The information reported to the TGA meets the criteria for confirmed TTS. However, the case remains under investigation as there are ongoing clinical investigations including consideration of other medical conditions.
This takes the total Australian reports of cases assessed as TTS following the AstraZeneca vaccine to 24. So far about 2.1 million doses of the AstraZeneca vaccine have been administered. Overall, 21 of these cases are considered confirmed and three are considered probable. Three of the four cases reported as probable in last week’s report have since been confirmed as TTS. The other case remains under investigation.