Europe’s drug regulator said on Friday that it could not confirm whether AstraZeneca’s COVID-19 vaccine has any influence on higher risks for unusual blood clots associated with low levels of blood platelets in women and younger adults. The European Medicine Agency (EMA) said in a statement it was requested by the European Commission to provide a scientific opinion following initial reports of thrombosis with thrombocytopenia syndrome (TTS) linked to AstraZeneca’s COVID-19 vaccine, known as Vaxzevria. “The evidence did not allow EMA to identify particular risk factors that make TTS more likely,” the drug regulator said. “Although spontaneous reports … have suggested that the risk may be higher in women and in younger adults, and lower after the second compared to the first dose, the limitations of the way the data is collected mean that none of these differences could be confirmed.” A committee that is responsible for elaborating EMA’s opinions on …