The European Medicines Agency (EMA) has established that there is a link between the AstraZeneca Covid-19 vaccine and blood clots. The agency maintains its guidelines, allowing the vaccine to be distributed as the benefits outweigh the risks. However, some European countries are restricting the vaccine to older age groups only. Blood clotting with low platelet counts are reported to be 1 in 250,000 according to the EMA. For more information on the vaccine, read the article on CNN by Rob Picheta here.