Vaccine responsiveness in premature infants.

The purpose of this review is to document adaptive immune responses in premature infants with a gestational age ≤32 weeks to the different vaccines used in the primary immunisation programme in the UK. Evidence suggests that these infants have impaired immune functioning that is consequent on maturational status and which resolve at variable time periods after birth - this impacts both on their risk of infection and response to vaccination. Assessing vaccine responsiveness can help establish whether the administration of additional vaccines is appropriate for a premature infant, and this may be determined either by vaccine immunogenicity or efficacy studies. The focus of the paper is immunogenicity studies for the following vaccines: tetanus, and diphtheria (toxoid vaccines), Haemophilus influenzae type b (Hib), meningococcal C (Men C) and pneumococcal (PnC) (subunit glycoconjugate vaccines), pertussis (subunit vaccine) and polio (inactivated vaccine). Data show that immunogenicity in premature infants is vaccine specific and whilst highly protective for the toxoid and inactivated preparations, responses to the subunit preparations are less optimal and consequently additional vaccinations or serology testing for ≤32 week gestation infants be considered.