epa09094391 A health worker injects a dose of the AstraZeneca COVID-19 vaccine at Casernes Hospital in Barcelona, Spain, 24 March 2021. Spain resumes the use of the AstraZeneca COVID-19 vaccine after a 10-day-long pause in its administration, after reports stated the vaccine could be associated with an increase in the risk of blood clotting disorders, doubts that were finally ruled out by the European Union&#039;s medicines regulator that declared the vaccine as safe.  EPA/Alejandro Garcia