Europe’s vaccine divide: As scientists scramble for answers to AstraZeneca blood clot puzzle, some nations opt for caution

For 18 hours a day, Andreas Greinacher and his team at Germany's Greifswald University Hospital have pored over blood samples from across Germany and Austria. Their mission: Trying to figure out how and why potentially deadly blood clots have appeared in a handful of patients who received AstraZeneca’s coronavirus vaccine. No link has been established with the vaccine, widely used in Europe and other countries, including Canada and India, and under review for possible approval in the United States.