I have a new situation: When Emily was 4 years old she came down with a case of the chicken pox. She is now 14 and her younger brother Victor has now caught the chicken pox from another child at school. Emily opts to stay home and take care of him. But I can use this background: Active immunity can also result from immunization. Immunization is the deliberate exposure of a person to a pathogen in order to provoke an immune response and the formation of memory cells specific to that pathogen. The pathogen is often injected. However, only part of a pathogen, a weakened form of the pathogen, or a dead pathogen is typically used. This causes an immune response without making the immunized person sick. This is how you most likely became immune to measles, mumps, and chicken pox. You can watch an animation showing how immunization brings about immunity at this link: http://www.biosolutions.info/2009/05/vaccination.html . What is an answer for this question: Will building an immunity to a pathogen increase or decrease the chances of infection by that pathogen.
Answer:
decrease