The European Medicines Agency (EMA), the European Union's drug regulator, on Friday found a possible link between Johnson & Johnson's COVID-19 vaccine and rare cases of blood clotting in deep veins.
During a Pharmacovigilance Risk Assessment Committee meeting, the agency said it found a possible link between venous thromboembolism (VTE) and the J&J 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," the agency wrote in its meeting highlights.
It is recommending that the condition be listed as a rare side effect.
The agency also recommends that immune thrombocytopenia (ITP) be listed as a side effect of the J&J vaccine and AstraZeneca's vaccine.
ITP is a bleeding disorder in which "the immune system mistakenly targets blood cells called platelets that are needed for normal blood clotting," the agency wrote.
While J&J said the conditions are rare, it will update the product information and continue to work closely with EMA and other government agencies, according to Reuters.
"We strongly support raising awareness of the signs and symptoms of rare events to ensure they can be quickly identified and effectively treated," the company said in a July statement.
The vaccines from both AstraZeneca and Johnson & Johnson have previously been associated with rare incidents of blood clotting.