COVID vaccine researchers had previously assumed mRNA COVID vaccines would behave like traditional vaccines. The vaccine’s spike protein — responsible for infection and its most severe symptoms — would remain mostly in the injection site at the shoulder muscle or local lymph nodes. But new research obtained by a group of scientists contradicts that theory, a Canadian cancer vaccine researcher said last week. “We made a big mistake. We didn’t realize it until now,” said Byram Bridle, a viral immunologist and associate professor at University of Guelph, Ontario. “We thought the spike protein was a great target antigen, we never...