New Immunizations for Children

Routine immunizations for children have markedly changed the epidemiology of many infectious diseases in the United States. Diphtheria, tetanus, and poliomyelitis are rare occurrences, and measles, mumps, and rubella have declined substantially. These successes have encouraged research into vaccines to prevent other serious bacterial and viral diseases. Although many vaccines are currently being developed, only four (those against Haemophilus influenzae, varicella, pertussis, and rotavirus) will be discussed in this article. They have been chosen because they have received considerable publicity and generated many questions from parents and physicians. HAEMOPHILUS INFLUENZAE Although exact incidence figures are not available in the United States, H influenzae causes about 20,000 serious illnesses per year in young children, with significant mortality and morbidity. Newer antibiotics and more Sophisticated intensive care have not reduced the death rate or the incidence of serious sequelae caused by H influenzae meningitis. Epiglottitis responds well to intubation and appropriate antibiotics but is life threatening without proper medical facilities. Invasive disease is seen almost exclusively with type b H influenzae and is correlated with the capsular polyribophosphate (PRP) of the organism. Antibody to its PRP provides protection from infection by the organism. Localized illness such as otitis media is frequently caused by non-type b organisms. The incidence of such infections would not be affected by anti-PRP antibody.