Biology is messy and you can not say for certain that there will never be a group of individuals with an autoimmune issue. That is why vaccines go through sever

Biology is messy and you can not say for certain that there will never be a group of individuals with an autoimmune issue. That is why vaccines go through several clinical trial phases. I recommend listening to this lecture about the process: https://youtu.be/35Idb_lCU4o?t=61 https://youtu.be/35Idb_lCU4o?t=61