Related Experiment Videos
Hib vaccination in infants born prematurely
P T Heath1, R Booy, J McVernon
1Department of Child Health and St George's Vaccine Institute, St George's Hospital Medical School, London, UK. pheath@sghms.ac.uk
Insights
Premature infants show lower antibody levels after Haemophilus influenzae type b (Hib) vaccination and may have a slightly increased risk of invasive Hib disease compared to full-term infants. However, Hib conjugate vaccines still provide substantial protection for premature babies.
Area of Science:
- Immunology
- Pediatrics
- Vaccinology
Background:
- Haemophilus influenzae type b (Hib) conjugate vaccines are crucial for preventing invasive Hib disease.
- Premature infants represent a vulnerable population with potentially altered immune responses to vaccination.
Purpose of the Study:
- To assess the immunogenicity and antibody persistence to polyribosyl-ribitol phosphate (PRP) in prematurely born infants.
- To evaluate clinical protection against invasive Hib disease in this cohort.
- To compare outcomes with infants born at full term.
Main Methods:
- A cohort of prematurely born infants (
- Anti-PRP antibody concentrations were measured and compared to a control group of term infants.
- National surveillance data (UK and Republic of Ireland, 1992-2000) tracked Hib vaccine failures.
Main Results:
- Premature infants exhibited significantly lower anti-PRP antibody concentrations at all measured time points compared to term infants.
- The relative risk of developing invasive Hib disease was 1.5 times higher in premature infants than in term infants (95% CI 0.9 to 2.6).
- While 18 premature infants experienced vaccine failure, this number was slightly higher than the expected 12 cases.
Conclusions:
- Hib conjugate vaccination elicits lower antibody responses in premature infants compared to their full-term counterparts.
- Premature infants may face an elevated risk of clinical vaccine failure, though this requires further investigation due to limited case numbers.
- Despite these findings, Hib conjugate vaccines remain highly protective for premature infants against invasive Hib disease.
Aims:
To document the immunogenicity and persistence of antibody to polyribosyl-ribitol phosphate (PRP) as well as the clinical protection against invasive Haemophilus influenzae type b (Hib) disease in premature infants immunised at the routine schedule.
Methods:
Blood was obtained at 2, 5, 12, and 64 months of age from a cohort of prematurely born infants (
Results:
Twenty seven prematurely born infants were followed to 5 years of age. Compared with term infants they had a significantly lower geometric mean concentration of anti-PRP antibody and/or a significantly lower proportion above one or both of the conventional protective antibody concentrations (0.15 and 1.0 micro g/ml) at all ages. A total of 165 cases of invasive Hib disease were identified over eight years of national surveillance. Eighteen were premature (<37 weeks); approximately 12 would be expected. The relative risk of UK premature infants developing disease compared with term infants was 1.5 (95% CI 0.9 to 2.6).
Conclusions:
Premature infants develop lower antibody concentrations than term infants following Hib conjugate vaccination. Premature infants may also have an increased risk of clinical vaccine failure, but interpretation is limited by the small number of premature infants developing invasive Hib disease over eight years of national surveillance. Overall, vaccination with Hib conjugate vaccines affords a high level of protection to premature babies.