Complex sentence: After that first encounter with anti-vaccine arguments, Reiss started reading more about the claims by people opposing vaccines and the refutations provided by experts, and became convinced that the answers given by scientists were solid and powerful.
Split into simpler sentences: After that first encounter with anti-vaccine arguments, Reiss started reading more about the claims made by people opposing vaccines and the refutations provided by experts. She became convinced that the answers given by scientists were solid and powerful.