Immune Status of Children One to Four Years of Age as Determined by History and Antibody Measurement

Measurement of serum antibody levels in children one to four years old, living in three city and one suburban census tract, revealed that 63 per cent of the total study population were susceptible to rubella and approximately 33 per cent had inadequate titers of measles antibody. Antitoxin levels to diphtheria and tetanus were low in 24 and 7 per cent respectively of the entire study group. A large proportion (57 per cent) of these children had serum antibody levels of less than 10 to one or more types of poliovirus. Many had low antibody levels after the recommended number of immunizations; others had not received adequate poliomyelitis vaccine. Although those with low levels may not contract paralytic disease, if reinfected with wild poliovirus, they may spread the infectious agent to susceptible persons in the environment. Increased effort should be made to immunize all preschool children. Advisory committees should consider the need for periodic reimmunization. (N Engl J Med 289:231–235, 1973)