#2. Diseases prevented by vaccines See the following links:
https://www.who.int/teams/immunization-vaccines-and-biologicals/diseases
https://www.dhs.wisconsin.gov/immunization/vpd.htm
#3. Old cemeteries. I could not find images of this, but I have been very stuck seeing this in person. Investigate it for yourself.
#4. Vaccination history (See the following link:
https://www.pbs.org/wgbh/nova/video/a-history-of-vaccination/