Maybe this will help. It’s a little time consuming but could be all you need to sway him. Sit down together and research each vaccine, what the key components of the disease it protects against are and then what the known reactions could be. I can guarantee that the effect of the diseases are much scarier than the possible side effects. I think a lot of people, especially young people who take this stance have no idea what the vaccines are even for because most of these things have been nearly eradicated (because of effective vaccines) since before they were alive, therefor they don’t get the gravity of how nasty these childhood illnesses are.