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Covid-19 Primary Care Resources

Coagulation disorders and anticoagulation treatment

Updated vaccination guidance for individuals with clotting and bleeding disorders and those on anticoagulation therapy

This information is sourced from the MHRA, The Green Book, chapter 14a, and PHE:

For the majority of individuals, the risk of recurrent thrombosis due to Covid-19 infection is far greater than the risk of extremely rare immune-mediated thrombosis in combination with thrombocytopaenia

The JCVI advises that those who have received their first dose of AZ vaccine should continue to be offered the second dose

Contraindications or cautions to receiving the AZ vaccine include:

  • A history of other extremely rare immune-mediated syndromes that are characterised by thrombosis in combination with thrombocytopaenia
  • This includes a previous episode of Heparin-Induced Thrombocytopaenia or the same specific clinical picture in association with anti-phospholipid syndrome
  • Anyone who experienced cerebral or other major blood clots occurring with low levels of platelets after their first vaccine dose of Covid-19 vaccine AZ should not have their second dose of AZ vaccine
  • These individuals may be offered an alternative Covid-19 vaccine

AZ vaccine in patients who already have a pre-exiting risk of blood clots:

  • A history of thromboses on its own is not a contraindication to the vaccine
  • If a patient has a history of DVT or PE without concurrent thrombocytopenia, then they can receive the AZ vaccine
  • Likewise, if they have had an arterial thrombosis eg myocardial infarction without thrombocytopenia then they can receive the AZ vaccine
  • Those diagnosed with thrombophilia, whether or not they are on long term anti-coagulation should be vaccinated with any of the available vaccines
  • A history of thromboses on its own (without thrombocytopaenia) following the first dose of AZ vaccine is not a contraindication to receiving their second dose
  • It is NOT recommended to take aspirin before vaccination with AZ, unless this is already part of your patient’s regular medications

Can patients receive the AZ vaccine if they have been or are currently thrombocytopenic?

  • Thrombocytopaenia on its own is not a contraindication to receiving the AZ vaccine


  • Individuals who are stable on anticoagulant therapy can be vaccinated 
  • Patients on warfarin should be up to date with their INR monitoring with an INR below the upper level of their therapeutic range 

Vaccination Method 

  • Use a fine needle (23G or 25G). 
  • Press firmly for 2 minutes following vaccination 
  • Advise patients of the risk of haematoma