You don’t have to suffer through an infection to gain immunity to some diseases. Immunity can also come about by vaccination. Vaccination is the process of exposing a person to pathogens on purpose so the person will develop immunity to them. In vaccination, the pathogens are usually injected under the skin. Only part of the pathogens are injected, or else weakened or dead pathogens are used. This causes an immune response without causing the disease. Diseases you are likely to have been vaccinated against include measles, mumps, and chicken pox.
Jane took her young son Ethan to the doctors for a check-up. While they were there her son got vaccines for measles and mumps.
Is Ethan more or less likely to get measles?