Immunity can be provided artificially by vaccination and other forms of immunization. A vaccine is a preparation containing the offending organism -- usually in a weakened form that will not cause the actual disease. When introduced into the body, the vaccine stimulates the body to produce antibodies against the disease. These antibodies often remain in the system for life, and the body is thus prepared to resist the actual disease.
A number of viral diseases can be prevented by immunization. There are vaccines for polio, measles, rubella (German measles), mumps, some strains of influenza, and chicken pox. A vaccine against the organism Hemophilus influenzae also is available. This vaccine prevents the most common cause of bacterial meningitis in children.
If immunization aims to confer long-term resistance to certain maladies, medications generally are a more immediate defense. We will cover medication in the next section. Read on.