Almost Extinct Diseases: Measles, Mumps, Rubella, and Pertussis

Abstract

Introduction The availability of effective vaccines led to a dramatic decrease in the number of cases of measles, mumps, rubella, and pertussis reported each year. However, several years after their introduction, small but significant outbreaks began to appear in urban settings among clusters of children, adolescents, and young adults. Some of those who became ill were members of families that did not accept vaccine for religious reasons or because of fear of adverse reactions. Others were "vaccine failures," the 5% to 10% who did not respond to injected antigens or responded with only transient low levels of protective antibody. However, the majority of children who are infected during community outbreaks of contagious disease are those younger than school age who never received the vaccine. The requirement for immunization before school attendance and the new practice of administering a second dose of measles, mumps, rubella (MMR) vaccine to children of school age has resulted in relatively good levels of immunity among those 5 years of age and older, but more vigorous efforts are needed to protect a higher proportion of those not yet in school. Estimates for the year 1993, based on the National Health Interview Survey (NHIS), revealed that 67.7% of children ages 19 to 35 months had received the series of vaccines recommended routinely: four doses of diphtheria and tetanus toxoids and whole-cell pertussis (DTP) vaccine, three doses of polio vaccine, and one dose of MMR.