Global infections: 130,784,257 Global deaths: 2,846,403 Nations with most cases: US (30,671,843), Brazil (12,953,597), India (12,485,509), France (4,802,545), Russia (4,520,879). Blood clots and the AstraZeneca Covid vaccine: is there a link? Even as the United Kingdom reported more blood clot cases in people who received the AstraZeneca vaccine, the health regulator said that the benefits of the jab far outweigh the risks. However, many governments are still concerned about the jab. The main condition causing alarm is when blood forms clots in the veins that run from the brain, a potentially fatal complication. This has also been combined with patients having unusually low platelets, resulting in heavy bleeding. One hypothesis, put forward by a team of researchers in Germany, is that the AstraZeneca vaccine could be provoking an overexcited immune response in some people, causing them to generate antibodies that target blood platelets.