Vaccination

Definition

Vaccination introduces a vaccine into the body to produce immunity and prevent specific diseases.

Description

Many diseases that once caused widespread illness, disability, and death are now prevented by vaccines in developed countries. Vaccines are medicines that contain weakened or dead bacteria or viruses. When a child receives a vaccine, his or her immune system responds by producing antibodies, substances that weaken or destroy disease-causing organisms. When the child comes in contact with live bacteria or viruses of the same kind that are in the vaccine, the antibodies prevent those organisms from making the child sick. Vaccines also stimulate the cellular immune system. In other words, the child becomes immune to the disease the organisms normally cause. Building immunity by using a vaccine is called immunization. Childhood immunizations are safe and remain the most effective way to prevent disease.

Vaccines contain antigens (weakened or dead viruses, bacteria, and fungi that cause disease and infection). When introduced into the body, the antigens stimulate the immune system response by instructing B cells to produce antibodies, with assistance from T-cells. The antibodies are produced to fight the weakened or dead viruses in the vaccine. The antibodies "practice" on the weakened viruses, preparing the immune system to destroy real and stronger viruses in the future. When new antigens enter the body, white blood cells (called macrophages) engulf them, process the information contained in the antigens, and send it to the T-cells so that an immune system response can be mobilized.

General use

In the early 2000s, children in the United States and in other developed countries routinely have a series of vaccinations that begins at birth. Vaccinations in children began about 1900 with the smallpox vaccine. In 1960 there were only five vaccines in eight shots. The number of vaccinations children receive has steadily increased since that time. As of 2004, children receive 11 different vaccines given in up to 20 shots by age two years. Given according to a specific schedule, these vaccinations protect against hepatitis B; diphtheria, tetanus, pertussis (whooping cough) (DTP); measles, mumps, rubella (German measles); varicella (chickenpox); polio; pneumococcus; and Haemophilus influenza type B (Hib disease, a major cause of spinal meningitis) and, in some states, hepatitis A. This series of vaccinations is recommended by the American Academy of Family Physicians, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention and is a requirement in all states before children can enter school. States make exceptions for children who have medical conditions such as cancer that prevent them from having vaccinations, and some states also make exceptions for children whose parents object for religious or other reasons.

Several vaccines are delivered in one injection, such as the measles-mumps-rubella (MMR) and diphtheria-tetanus-pertussis (DTP) combinations.

Vaccines are used in several ways. Some vaccines, such as the rabies vaccine, are given only when a child comes in contact with the virus that causes the disease, such as through a dog bite.

Recommendations for other vaccines and immunobiologic medicines depend on the child's health status or area of world where the family might travel. Such treatments are vaccine or immune globulin for hepatitis A, typhoid, meningitis, Japanese encephalitis, and rabies.

In addition the uses discussed above, vaccines are available for preventing anthrax, cholera, plague, tuberculosis, and yellow fever. Most vaccines are given as injections, but a few are taken orally.

The administration of vaccines to meet travel requirements should not interfere with or postpone any

of the routine childhood immunizations. If necessary, the routine immunization schedule can be accelerated to give as many vaccines as possible before departure. Decisions about vaccinations for children with chronic illnesses are made with the child's doctor.

Parents who are planning to travel with children to another country should find out what vaccinations are needed. Some vaccinations may be needed 12 weeks before the trip, so getting this information early is important. Many major hospitals and medical centers have travel clinics that provide this information. The traveler's health section of the Centers for Disease Control and Prevention also has information on vaccination requirements.

A vaccination health record helps parents and healthcare providers keep track of a child's vaccinations. The record should start when the child has his or her first vaccination and should be kept up-to-date with each added vaccination. While most doctors follow the recommended vaccination schedule, some flexibility is allowed. For example, vaccinations scheduled for age two months may be given anytime between six to ten weeks. Slight departures from the schedule do not keep the child from developing immunity, as long as all the vaccinations are received close to the right times.

Content licensed from:

Author Info: Aliene S. Linwood RN, DPA, FACHE, Thomson Gale, Gale, Detroit, Gale Encyclopedia of Children's Health, 2006

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.