Meeting highlights from the Pharmacovigilance Risk Assessment Committee of the European Medicines Agency, from 27 to 30 September 2021


  • Assessment of rare cases of venous thromboembolism with the Janssen COVID-19 vaccine

The Pharmacovigilance Risk Assessment Committee (PRAC) has concluded that there is a possible link between rare cases of venous thromboembolism (VTE) and the Janssen COVID-19 vaccine.

VTE is a condition in which a blood clot forms in a deep vein, usually in a leg, arm, or groin, and may travel to the lungs causing a blockage of the blood supply, with possible life-threatening consequences. This safety issue is distinct from the very rare side effect of thrombosis with thrombocytopenia syndrome (TTS) (i.e. blood clots with low blood platelets).  

VTE was included in the risk management plan for the Janssen COVID-19 vaccine, as a safety concern to be investigated, based on a higher proportion of cases of VTE observed within the vaccinated group versus the placebo group, in the large clinical study that was used to authorize this vaccine. The issue has been closely monitored. 

The PRAC also reviewed evidence from the post-marketing setting – that is, data gathered while the vaccine is being used in vaccination campaigns. When taking all evidence into account, the committee concluded that there is a reasonable possibility that rare cases of VTE are linked to vaccination with the Janssen COVID-19 vaccine.

The committee is therefore recommending that VTE be listed in the product information as a rare side effect of the Jansen COVID-19 vaccine, together with a warning to raise awareness among healthcare professionals and people receiving the vaccine, especially those who may have an increased risk of VTE.

  • PRAC assessment of cases of immune thrombocytopenia with the Vaxzevria and Janssen COVID-19 vaccines The PRAC assessed cases of immune thrombocytopenia (ITP) reported following vaccination with the Vaxzevria vaccine (formerly AstraZeneca COVID-19 vaccine), as well as with the Janssen COVID-19 vaccine.

ITP is a condition in which the immune system mistakenly targets blood cells called platelets, which are needed for normal blood clotting. Very low levels of blood platelets can be associated with bleeding, and have serious health consequences.

The committee assessed all of the available data, and recommended updating the product information of both vaccines to include ITP as an adverse reaction with unknown frequency.

Furthermore, a warning statement has been agreed upon to highlight the fact that cases of very low levels of blood platelets have been reported very rarely, usually within the first four weeks following vaccination with the Janssen or Vaxzevria COVID-19 vaccine.

If an individual has a history of ITP, the risk of developing low platelet levels should be considered before vaccination, and platelet monitoring is recommended after vaccination with either of these vaccines.

The PRAC will continue to monitor new information, and will take any further actions that may be necessary.


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