Health.  Covid  19: what are the risks associated with vaccines?  freed Dauphine

Health. Covid 19: what are the risks associated with vaccines? freed Dauphine

Vaccination against Covid-19 is suspected – in very rare cases – to expose people to an increased risk of thromboembolic diseases and thrombocytopenia.

The first leads to the formation of clots in the veins, or pulmonary embolism if a clot blocks the pulmonary artery. The second corresponds to a decrease in platelet count and an increased incidence of bleeding.

To dig deeper into the topic, researchers in Denmark, Finland and Norway conducted a study on the anti-Covid vaccines from the labs of Pfizer-BioNTech, Moderna and AstraZeneca.

The cohort consisted of 265,339 patients hospitalized between January 1, 2020 and May 16, 2021 with coronary artery disease, bleeding disorders, or cerebrovascular disease.

An increased risk of cerebral thrombosis


• AstraZeneca’s vaccine ‘increases the risk of cerebral venous thrombosis and thrombocytopenia,’ reports Professor Jacob Dag Berild, first author of the study;
• No significant association was observed for messenger RNA vaccines from Pfizer-BioNTech and Moderna.


These risks of thrombocytopenia, but also coagulation disorders, were highlighted by the National Medicines Safety Agency (ANSM) in relation to the AstraZeneca vaccine in a letter sent to healthcare professionals in March 2021.

Cases of thromboembolic disease and thrombocytopenia have actually been reported within 7 to 14 days after vaccination, particularly in women under 55 years of age.

However, due to the very low incidence of these accidents, the ANSM recalls that “the benefits [de la vaccination] the risks outweigh the very likely association with very rare cases of blood clots associated with low doses of platelets.”

When to consult?

If you have just been vaccinated against Covid-19, here are the symptoms that should prompt you to seek advice if they occur in the hours or days following your injection: “Shortness of breath, acute chest pain, leg swelling or persistent abdominal pain” , the ANSM passed on.

The same applies if you experience neurological symptoms such as “severe or persistent headache, blurred vision” after the vaccination.

Source: Jama Network, June 14, 2022.