The European Medicines Agency (EMA) found a possible link between the development of very rare blood clots and the COVID-19 vaccine developed by the pharmaceutical company Janssen, but confirmed that the benefit-risk balance of this preparation remains positive.
After two weeks of investigations of six cases of very rare thrombembolisms detected in patients vaccinated with Janssen in the United States, the EMA decided to add a warning of the possible, very small risk of developing blood clotting to the vaccine package insert, but continues to recommend its use in the European Union (EU).
At a meeting of the EMA safety committee (PRAC), European scientists concluded that “these events should also be included as very rare side effects” of the vaccine, which, as of April 13, had been received by more than 7 million people in the United States, a country that has suspended the use of Janssen until the investigation of these thromboembolic events is completed.
“The committee considered all currently available evidence, including eight reports from the United States of severe cases of unusual blood clots associated with low blood platelet levels, one of which was fatal,” the EMA added in a statement. , which compared these cases to thrombi that occurred with the AstraZeneca vaccine.
All the cases occurred in people under 60 years of age, within three weeks after vaccination, and the majority were women, says the European regulator, which warns that, based on current evidence, “no risk factors have been confirmed specific ”, such as age, sex and medical history of development of these symptoms.
The Agency believes that healthcare professionals and patients receiving the Janssen vaccine should be aware of the possibility of very rare cases of blood clotting combined with a low level of platelets in the blood within three weeks of vaccination. .
Beyond adding this information to the product, the EMA considers that the risk associated with COVID-19, a disease that can lead to hospitalization or death of patients, continues to be greater than the possible risk of developing blood clotting, therefore that “the overall benefits of the vaccine outweigh the risks of side effects.”
In addition, he added that the use of available COVID-19 vaccines will take into account the situation of the pandemic and the availability of the vaccine in different EU countries, and pointed out that a plausible explanation for these clotting cases is that they are an immune response similar to that seen with heparin treatments.