The European Medicines Agency (EMA) has launched an investigation into a possible link between the Johnson & Johnson Covid-19 vaccine and four reported cases of blood clots, one of which proved fatal.
The EMA, which recently confirmed blood clotting in the brain as a “very rare” side-effect of the AstraZeneca jab, said a safety committee “has started a review of a safety signal to assess reports of thromboembolic events” in people who got the Johnson & Johnson vaccine.
“Four serious cases of unusual blood clots with low blood platelets have been reported post-vaccination with Covid-19 Vaccine ‘Janssen’ (J&J’s European subsidiary),” the EMA said.
“One case occurred in a clinical trial and three cases occurred during the vaccine rollout in the USA. One of them was fatal.”
“These reports point to a ‘safety signal’, but it is currently not clear whether there is a causal association between vaccination with COVID-19 vaccine Janssen and these conditions.”
The EMA is “investigating these cases and will decide whether regulatory action may be necessary, which usually consists of an update to the product information”.
The Johnson & Johnson vaccine, which has already been approved by the EMA for use throughout the EU, is to begin being administered before the end of April.
The shot has been found to have a 67% success rate in preventing infection and trials suggest it is fully effective in preventing hospital admissions and death from Covid-19.
The one-shot Johnson & Johnson vaccine has only been used in the United States so far however.
In response to news of the investigation, Johnson & Johnson said “at present, no clear causal relationship has been established between these rare events and the Janssen COVID-19 vaccine.”