In the early 1900s, Imogene Rechtin started a crusade to get people to stop kissing socially as a way to stop disease spread. Her argument was sound, but she was largely dismissed as being uptight.
Research:

Robert Moses and the Shaping of New York, Part 2
42:12

Robert Moses and the Shaping of New York, Part 1
41:59

SYMHC Classics: Eradication of Smallpox
43:25