Vaccination is the administration of antigenic material to stimulate the individual’s immune system to develop adaptive immunity or antibodies to a pathogen. Vaccines can prevent or ameliorate morbidity and/or mortality from infection.
In common speech, vaccination and immunization have a similar meaning. This distinguishes it from inoculation, which uses unweakened live pathogens, although in common usage either can refer to an immunization.
The active agent of a vaccine may be intact but inactivated (non-infective) or attenuated (with reduced infectivity) forms of the causative pathogens, or purified components of the pathogen that have been found to be highly immunogenic (e.g. outer coat proteins of a virus). Toxoids are produced for immunization against toxin-based diseases, such as the modification of tetanospasmin toxin of tetanus to remove its toxic effect while retaining its immunogenic effect.
The Centers for Disease Control and Prevention (CDC) recommends vaccination as a way to control and prevent disease outbreaks in the United States. Vaccine schedules include immunizations against contagious diseases such as measles, mumps, pertussis, etc…
The following are vaccination schedules designed according to age range by the CDC:
The World Health Organization (WHO) reports that licensed vaccines are currently available to prevent or contribute to the prevention and control of around twenty-five preventable infections.