How do vaccinations work to protect individuals and communities from infectious diseases, and what is herd immunity?

V acc in ations work by introdu cing a weak ened or in activ ated form of a path ogen into the body , which triggers an imm une response without causing ill ness . This imm une response helps the body develop imm unity to the disease , so that if the person is exposed to the actual path ogen in the future , their imm une system can quickly recognize and fight it off . \n \n V acc in ations are an important tool for protect ing individuals and communities from inf ect ious dise ases . By v acc in ating a large portion of a population , known as her d imm unity , the spread of disease can be prevent ed . H erd imm unity occurs when a sufficient number of people in a community are imm une to a disease , either through v acc ination or natural in fection , so that the disease cannot spread easily from person to person . This protect s individuals who are not imm une , such as young children or people with comprom ised imm une systems , from becoming inf ected . \n \n It ' s important to note that her d imm unity only occurs when a large portion of the population is imm une , and that individuals who are not imm une , such as those who are too young to be v acc in ated or who are imm uno comp rom ised , still need to take pre ca utions to protect themselves from in fection . </s>