The risk assessment committee (PRAC) of the European Medicines Agency (EMA) is carrying out an investigation into reports of a second possible side effect of the AstraZeneca vaccine against Covid-19.
The PRAC has already examined the link between the vaccine, which now calls itself Vaxzevria, and blood forming in patients who received it. That investigation concluded that the clots, which coincide with low volumes of blood platelets, are a very rare side effect, and advised healthcare professionals and people receiving the vaccine to remain aware of the possibility of blood clots combined with low levels of blood platelets occurring very rarely within two weeks of vaccination.
Now the committee has turned its attention to another problem, known as capillary leak syndrome, also associated with Vaxzevria.
That syndrome involves the leakage of blood from the capillaries – the smallest of all the blood vessels – and into the surrounding tissues, causing swelling and a fall in blood pressure which could be dangerous for people whose blood pressure already tends to be low.
So far only five cases have been reported, and it remains unclear whether there is any link between the vaccine and the leakage. The reports appeared on the EMA’s EudraVigilance database as ‘safety signals’ – reports of the sudden appearance of new or changed side effects of drugs that require further investigation.
Finally, PRAC is also investigating reports of the formation of clots in people who received the new Janssen vaccine against Covid. Four reports have been filed, one during a clinical trial and three during vaccine use in the United States. One of the sufferers died.
Janssen has been approved for use in the EU since March, but rollout has not yet started in any member state.
PRAC said it would investigate and recommend regulatory action if necessary.