"AEMPS, other regulators and the European medicines agency EMA are gathering data and conducting a thorough investigation to determine whether, in addition to a temporal connection to the administration of the vaccine, there was a possible causative relationship", a statement read.
The 43-year-old received the first dose of the AstraZeneca vaccine on 3 March and reported a headache within hours, which was dismissed as a common side effect. She sought medical help 10 days later after her symptoms worsened. The surgery revealed a brain bleed and swelling. She died on Monday.
The Health Ministry said she had suffered an ischemic stroke that transformed into a brain haemorrhage.
The woman was among three people reported to have developed a combination of unusual symptoms — blood clots and a low count of platelets — which may point to an "abnormal activation of the coagulation system, associated with the formation of blood clots in unusual places".