COVID-19 VACCINE ASTRAZENECA

04 April 2021

3 April 2021

The Australian Technical Advisory Group on Immunisation (ATAGI) has released an updated statement on a specific clotting condition reported after COVID-19 vaccination. There have been rare cases of thrombosis associated with thrombocytopenia in persons who have received the COVID-19 vaccine AstraZeneca, with the period of concern 4-20 days after vaccination. The majority of these are associated with cerebral venous sinus thrombosis (CVST), but thrombosis in other parts of the body (e.g. intra-abdominal venous systems) have also been reported. In some cases, the clinical features are similar to heparin induced thrombocytopenia (HIT).

There is not a higher overall rate of other more common types of blood clots after COVID-19 vaccination (including deep venous thrombosis (DVT) and pulmonary embolism (PE)).

Doctors are asked to:

  • Read the ATAGI AstraZeneca statement ‘Updated ATAGI statement for healthcare providers on a specific clotting condition being reported after COVID-19 vaccination’.
  • Be alert for signs of thrombosis associated with thrombocytopenia in persons who have received the COVID-19 vaccine AstraZeneca 4-20 days earlier including: new, severe or persistent headache not settling with analgesia, features of raised intracranial pressure (acute severe headache, vomiting, confusion), focal neurological deficits and/or seizures, or other significant symptoms e.g. severe abdominal pain.
  • Be alert for any persistent unexpected or severe adverse event following any immunisation.
  • Continue the roll-out of the COVID-19 vaccination program and provide to individuals receiving or considering vaccination the ‘ATAGI statement for consumers on a specific clotting condition being reported after COVID-19 vaccination’. 
  • Advise patients of the common side effects of COVID-19 vaccine AstraZeneca (fever, sore muscles, tiredness and headache), their timing (usually start within 24 hours of vaccination and last for 1-2 days) and the importance of seeking medical care if symptoms are severe, unusual or persistent.
  • Do not administer COVID-19 vaccine in persons who have a past history of CVST or HIT, until further information is available.

Doctors with patients with suspected thrombosis associated with thrombocytopenia after AstraZeneca vaccine are asked to:

  • Refer to a hospital emergency department any patient with suspected CVST or other thrombosis associated with thrombocytopenia.
  • Take initial investigations: full blood count (to look for thrombocytopenia), D-dimer, fibrinogen, and imaging as clinically indicated.
  • Consult with the haematologist on call if screening tests suggest HIT-like thromboses.
  • Do not give these patients heparin or platelet transfusions

Dr Louise Flood – Director, Communicable Disease Control Branch

For all enquiries please contact the CDCB on 1300 232 272