Edward Jenner discovered vaccinations. He found that some of the dairymaids who worked with cows had suffered lesions on their hands, and that these dairymaids were immune to the more severe smallpox. Then, he inoculated James Phipps with material from the lesions on a dairymaids’ hands. Which best explains why Jenner decided to infect Phipps?
The material contained antibodies that could destroy the smallpox pathogen.
The material contained pathogens that were similar to but weaker than the smallpox pathogen.
The material had oxygen that could help the cells of the body fight off smallpox infection.
The material contained a pathogen that could attack the smallpox pathogen.