Childhood Immunizations

Childhood immunizations have been the most effective way to control the extensive transmission of infectious diseases. Immunizations have the potential to protect children from life-threatening diseases, save the community from widespread epidemics, and improve overall global public health. With the development of vaccines, preventing the spread of infectious diseases through the use of immunizations has been a remarkable success.

Vaccines are designed to protect individuals from disease by eliciting an immune response in the body. Vaccines cause the human body to perceive that it is being invaded by a foreign pathogen, or disease-caus-ing organism. The body then produces antibodies. If the pathogen was to invade the body again, the antibodies would recognize and destroy it.

Vaccines can be made in a variety of ways. All vaccines are designed to prevent future infections using the same mechanism of triggering an immune response in the body. There are currently four different types of traditional vaccines. Live attenuated vaccines are weakened forms of the pathogen. They generally produce a long-lasting immune response, but can potentially change back to their original pathogenic form. Inactivated vaccines are a killed form of the microorganism. These vaccines create [Page 394]a short-lived immune response and often require subsequent doses in order to become effective. Toxoid vaccines allow the body to think that it is a toxin released by certain toxin-producing bacteria. These vaccines produce an immune response against a specific toxin that is released into the bloodstream by toxin-producing bacteria. Subunit vaccines are generally vaccines that consist of a fragment of the pathogen. These vaccines can also produce an adequate immune response during future infections.

Vaccines must be administered in a timely manner in order to be most effective at producing an immune response in the body. According to the updated Centers for Disease Control and Prevention's (CDC) Recommended Immunization Schedule for 2007, the standard immunization series administered between 0 and 18 months include four doses of diphtheria, tetanus, and pertussis (DPaT) vaccine, three doses of Rotavirus (Rota) vaccine, three doses of polio vaccine, three doses of Haemophilus influenzae type b (Hib) vaccine, three doses of Pneumococcal vaccine (PCV), and three doses of hepatitis B (HepB) vaccine. The first dose of the measles, mumps, and rubella (MMR) vaccine and the varicella vaccine is recommended at the age of 1, while the second dose of these vaccines is recommended between 2 to 4 years of age. The immunization series also recommends two doses of the hepatitis A (HepA) vaccine for children older than the age of 1 and a yearly influenza vaccine. Following this immunization schedule in a timely manner will significantly reduce the risk of contracting these infectious diseases during the remainder of a child's life.

Immunizations have been successful in eradicating diseases worldwide. As a result of the Smallpox Eradication Program launched by the World Health Organization (WHO), the last case of smallpox in the world was seen in 1977. The eradication of smallpox was one of the most significant public health interventions in history. Similarly, diseases such as measles, polio, diphtheria, tetanus, pertussis, rubella, mumps, and Hib are no longer prevalent because of the widespread implementation of immunizations. With the development of eradication programs, the WHO continually aims to eliminate infectious diseases at the global level through the use of immunizations.

...