Very rare cases of transverse myelitis have been reported following administration of the Covid adenoviral vector vaccines AstraZeneca and Johnson & Johnson. And the Prac Pharmacovigilance Committee of the Ema drug agency has decided to add this pathology as an adverse reaction of the two shield products, of unknown frequency. This is what the EMA reports, summarizing the conclusions that emerged from the last meeting of the pool of experts which was held from 10 to 13 January. The Prac recommended that the product information be changed for both vaccines, including a warning to raise awareness among healthcare professionals and the people to whom they are administered about these cases. Transverse myelitis (Tm) is a rare neurological condition characterized by inflammation of one or both sides of the spinal cord. It can cause weakness in the arms or legs, sensory symptoms (such as tingling, numbness, pain or loss of aching sensation), or problems with bladder or bowel function.The committee reviewed available information on globally reported cases , including those in the European database for suspected side effects (EudraVigilance) and data from the scientific literature, for both vaccines. And the analysis concluded that “a causal relationship between these two vaccines and transverse myelitis is at least a reasonable possibility. The benefit-risk profile of both vaccines remains unchanged.” The EMA will continue to “monitor this issue closely”. In the meantime, however, the EU regulatory body invites health workers and people who receive vaccines to pay attention to any symptoms so that early diagnosis, supportive care and treatment are possible. For those who, after the injection, develop symptoms of Tm, the advice of the EMA is to “consult a doctor immediately”.