AstraZeneca & Blood Clots

Posted by: katiefern - Posted on:

On Wednesday 7th April, the European Medicines Agency (EMA) stated that blood clots with low blood platelets should be listed as very rare side effects of the Oxford-AstraZeneca (AZ) COVID vaccine.

Please see the attached link which helps to provide some guidance and reassurance.

COVID-19 vaccination and blood clotting – GOV.UK (

Exceptional circumstances in which a different second vaccine to the first can be given 

In addition to giving a different second vaccine where the first vaccine is unknown or was a vaccine given abroad that is not available in the UK, there are certain other situations in which it may be appropriate to give a different second vaccine to the first, providing there are no contraindications. 

These are: 

Housebound patients or care home residents 

Housebound patients or care home residents who received the Pfizer BioNTech or Moderna vaccine for their first vaccination in a hospital setting but are resident in a nursing home or are newly housebound when the second dose is due. As these individuals would have to travel to a vaccination centre to receive a second dose of the same vaccine which may not be suitable or possible, they should be vaccinated at home or in the care home with the AstraZeneca vaccine (which is easier to transport) if appropriate after clinical assessment.

Individuals who experience severe adverse reactions after the first dose, including: 

• people with severe allergies/anaphylaxis to the vaccine or its components (for example, polyethylene glycol (PEG)) 

• after discussion with, and on the advice of, an allergy specialist, people with idiopathic anaphylaxis or a history of anaphylaxis to multiple other medicines

• individuals who experience a clotting episode with concomitant thrombocytopenia following the first dose of AstraZeneca vaccine

If an individual experienced a severe adverse reaction to their first dose of COVID-19 vaccine, advice in the Green Book COVID-19 chapter regarding second doses should be followed and expert clinical opinion from a specialist should be sought if further advice is required.

Vaccine supply not available locally

It is not recommended to give a different second vaccine simply because the same vaccine is not available that day. If all efforts to enable an individual to receive the same vaccine at another time and/or location have been exhausted, it may be necessary to use a different vaccine where the risk of not vaccinating is greater than the risk of further delay.

Information for healthcare professionals on blood clotting following COVID-19 vaccination – GOV.UK ( (info above from pg 14)

COVID-19 Greenbook chapter 14a (

COVID-19 vaccination programme guidance for healthcare workers (