The rollout of the vaccine – which had been authorized for use in the EU on March 11 – was put on hold by J&J last week after it became aware of the blood clots. In the US, authorities also recommended a similar pause while the blood clot cases were investigated.
Issued today, the EMA notes the cases reviewed were very similar to those that occurred with AstraZeneca’s COVID-19 vaccine. In both cases, it has concluded that the benefit-risk analysis remains positive and that blood clots should be listed as a vary rare side effect for the vaccines.
Cases occured in under-60s
As of 13 April, over 7 million people had received Janssen’s vaccine in the US. In assessing the vaccine, the EMA’s PRAC committee assessed available information: including eight reports of serious cases of unusual blood clots associated with low levels of blood platelets, one of which had a fatal outcome.
All cases occurred in people under 60 years of age within three weeks of the one-dose vaccination, the majority in women. Specific risk factors have not been confirmed.
“Healthcare professionals and people who will receive the vaccine should be aware of the possibility of very rare cases of blood clots combined with low levels of blood platelets occurring within three weeks of vaccination.
“COVID-19 is associated with a risk of hospitalisation and death. The reported combination of blood clots and low blood platelets is very rare, and the overall benefits of COVID-19 Vaccine Janssen in preventing COVID-19 outweigh the risks of side effects.”
PRAC says one plausible explanation for the combination of blood clots and low blood platelets is an immune response, leading to a condition similar to one seen sometimes in patients treated with heparin called heparin induced thrombocytopenia, HIT.
The EMA’s scientific assessment looks at the safe and effective use of COVID-19 vaccines. The use of the vaccine and how it is distributed is down to individual member states.
Johnson & Johnson is yet to comment on the EMA's advice today and its plans for EU vaccine distribution moving forward.