Vaccines. Nothing strikes debate among parents and health care professionals like vaccination. Like a lot of parents, we went back and forth about what to do. There was a lot of that influenced our decision but the charts on the following link is what truly solidified our decision.
I originally found these charts straight from the CDC themselves but of course I haven't been able to find it recently. These charts are 'zoomed out' disease mortality charts. The charts typically given by your pediatrician show disease death rates starting from around 1950 (or whenever a typical vaccine was introduced) until 1990. If you zoom out to around 1900 you will see that various diseases were already on their way out. WAY on their way out.