When I received my shots before going to desert storm I ran a high fever for 24 hours, then was fine. Kinda what you’d expect from a flu vaccine but higher fever and chills. We got 5-6 shots. I think everybody’s immune system is different, and it can trigger issues in some kids. Mine are all vaccinated and fine for the most part. One of my kids has very light autistic tendencies, but for some reason lots of kids do. Tics and such, plus social issues. I think the pros outweigh the cons.