The reason for the dramatic decline in the number of measles cases from 1960s to 2010 in the United States was because the vaccine? 1. Contained pathogens to fight against this highly contagious virus.
2. Prevented the development of serious complications after infection.
3. Exposed many people to a weakened form of the measles virus, making them immune.
4. Contained an antibiotic that killed the measles virus, preventing its spread.