Routine immunisation of preterm infants.

Fifty one preterm infants (26-36 weeks' gestation) were enrolled in a study of their immunological responses to diphtheria, tetanus, pertussis, and polio antigens eight to 12 weeks after their primary courses had been completed. Samples from 21 infants born at full term were also analysed. Many infants were able to start immunisation at 3 months of age. Premature infants who are immunised as soon as possible after 3 months of age develop adequate antibody responses.