Thanks to immunizations, diseases such as polio, mumps and diphtheria are almost unheard of today. Because they are no longer widespread, preventing these diseases may not seem a top priority. But immunizations are still of utmost importance, says Dr. Jerold Woodhead, associate professor of pediatrics at the University of Iowa College of Medicine and a staff physician at UI Hospitals and Clinics. "Immunizations protect individuals against diseases that would cause them or others in the community serious problems," Woodhead says.

Vaccines prompt the body to produce antibodies, which block the development of infection. Some vaccines produce enough antibodies in only one dose. Others require additional doses --boosters --to build up enough antibodies for protection.

Immunization laws vary among states. In Iowa, the following vaccines are required before a child enters any licensed child care facility or school: diphtheria, tetanus, pertussis, polio, measles, mumps and rubella. The haemophilus B vaccine, which protects against meningitis, is not yet required but strongly recommended.

The Iowa Department of Public Health has a recommended schedule of immunizations, which is available from the department or any pediatrician. The first vaccines should be given at 2 months, followed by boosters at various intervals.

"Without proper immunization, the number of cases of dangerous diseases can dramatically increase, as seen with the resurgence of measles," Woodhead says. In 1983, there was an all-time low of only 1,500 reported measles cases in the United States. About 28,000 cases were reported in 1990, including 60 deaths, most of whom were young, unimmunized children. "The risk of death from measles is much higher for children under the age of 5 to 18 months," he says.

Now, Iowa requires an additional measles booster before a child enters kindergarten. Older students and adults should also receive boosters because previous doses may not provide sufficient protection. "Boosters remind the body how to make the measles antibody and protect itself," Woodhead says.

Adverse reactions to immunizations are rare and the risk of complications is far less than the risk to a child and the community from being unimmunized. For example, only one in several thousand children will experience severe side effects from the pertussis (whooping cough) vaccine, but one child in every hundred who gets the disease before age 6 months dies, Woodhead says.

One reason some children are not properly vaccinated is cost. Today it costs $91.20 to fully immunize a child by school age compared to $6.69 in 1982, according to the Centers for Disease Control. Iowa provides immunization assistance to qualified families through child health and county clinics.

National Immunization Week is September 21-29, and "it promotes immunization as a major preventive measure to help increase the health of people in our country," Woodhead says. "Parents need to be responsible for getting their children immunized, beginning early in life," he adds.