Vaccination has eradicated smallpox worldwide and prevents such diseases as cholera, rabies, and typhoid fever. Vaccines work with the immune system's ability to recognize and destroy foreign proteins (antigens) that it determines are
nonself. Scientists are using this same principle to help the body recognize antigens peculiar to cancer cells. It is also applied in an experimental birth control vaccine that tricks the immune system into believing that human chorionic gonadotropin (HCG), a hormone secreted by a developing fertilized egg, is foreign, thus inactivating it and inducing menstruation even if fertilization has occurred. Vaccines are also used to control animal pests by conferring temporary infertility.
Vaccination programs have been notably successful in the United States. For example, in 1998 the Centers for Disease Control and Prevention reported only one case of poliomyelitis, one of diphtheria, 34 of tetanus, and 89 of measles. Despite the availability of vaccines, many thousands of people in the United States still die each year from vaccine-preventable diseases such as hepatitis and influenza.
Immunization against 17 diseases is recommended for young children and adolescents: hepatitis B (HepB); rotavirus; diphtheria, tetanus (lockjaw), and pertussis (whooping cough), given together as DTaP (formerly DTP) and, for older children, Tdap; Haemophilus influenzae b (Hib); poliomyelitis (IPV); pneumococcal infections, including pneumonia, meningitis, and bacteremia (PCV and PPV); measles, mumps, and rubella, given together as MMR; chickenpox (Var); hepatitis A (HepA); influenza; Neisseria meningitidis (meningococcal meningitis; MCV4, MPSV4); and human papillomavirus (HPV). Vaccination for shingles (herpes zoster) is recommended for persons aged 50 yearsor older, and annual vaccination for influenza is recommended for everyone six months or older. Researchers are working to develop combination vaccines that would simplify vaccine administration. Immunization against diseases such as yellow fever may be necessary before traveling to some countries. In 2002 the U.S. government decided to reinstitute smallpox vaccination for many military, health-care, and emergency personnel because of concern about a possible bioterror attack using smallpox.
See also inoculation.
See study by A. Allen (2007).
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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