The second dose of the AstraZeneca Covid vaccine is safe. The AIFA affirms this, adding however that “in subjects under the age of 60 the administration of Vaxzevria remains an open issue, and on which there are margins of uncertainty”. The clarification came in an in-depth document on post-vaccine thromboembolic complications with AstraZeneca and Johnson & Johnson. Despite these uncertainties, regarding the second dose for the ‘under 60’ vaccinated with AstraZeneca, it is specified that “the completion of the vaccination schedule represents the strategy to combat the spread of the Sars-Cov-2 virus that guarantees the best level of protection”. “Preventive use of antithrombotic drugs is strongly discouraged” The document then highlights that “in the face of a risk of serious adverse events, such as major bleeding, which is well quantifiable and relevant, and an unproven benefit in terms of reducing thromboembolic risk very low, the preventive prescription of antithrombotic drugs in vaccinated subjects is strongly discouraged. It is understood that these drugs can be continued in patients already under treatment “. Experts thus answer the question of whether there are drugs capable of preventing these thromboembolic manifestations. According to the Group, “it should be emphasized that there is no scientific evidence to support the hypothesis that acetylsalicylic acid (Asa) or low molecular weight heparins (Ebpm) are effective in reducing the risk of these very rare thrombotic events in subjects vaccinated against Covid-19 with Vaxzevria. “Furthermore,” the most common thrombophilic conditions present in the population cannot be the determinant of cases “of atypical thrombotic events. “and therefore their systematic research before vaccination is in no way recommendable”. When asked if factors have been identified capable of identifying the subjects at greater risk of developing thromboembolic manifestations, the experts respond by clarifying that “at the moment, the lack of definition of a unitary pathophysiological mechanism underlying the rare cases of thrombosis of the cerebral venous sinuses and / or the splanchnic district associated with Vaxzevria vaccination makes it impossible to identify risk factors to look for in the general population “. The document (structured in questions and answers) represents the conclusions of the expert group and is” aimed at providing non specialists and health personnel the information currently available to identify early and manage this very rare adverse event in the most appropriate way “, concludes AIFA.