Impaired Haemophilus influenzae Type b Transplacental Antibody Transmission and Declining Antibody Avidity through the First Year of Life Represent Potential Vulnerabilities for HIV-Exposed but -Uninfected Infants
Year: 2014
Type: article
Study design: Observational Study
Abstract: To determine whether immune function is impaired among HIV-exposed but -uninfected (HEU) infants born to HIV-infected mothers and to identify potential vulnerabilities to vaccine-preventable infection, we characterized the mother-to-infant placental transfer of Haemophilus influenzae type b-specific IgG (Hib-IgG) and its levels and avidity after vaccination in Ugandan HEU infants and in HIV-unexposed U.S. infants. Hib-IgG was measured by enzyme-linked immunosorbent assay in 57 Ugandan HIV-infected mothers prenatally and in their vaccinated HEU infants and 14 HIV-unexposed U.S. infants at birth and 12, 24, and 48 weeks of age. Antibody avidity at birth and 48 weeks of age was determined with 1 M ammonium thiocyanate. A median of 43% of maternal Hib-IgG was transferred to HEU infants. Although its level was lower in HEU infants than in U.S. infants at birth (P < 0.001), Hib-IgG was present at protective levels (>1.0 μg/ml) at birth in 90% of HEU infants and all U.S. infants. HEU infants had robust Hib-IgG responses to a primary vaccination. Although Hib-IgG levels declined from 24 to 48 weeks of age in HEU infants, they were higher than those in U.S. infants (P = 0.002). Antibody avidity, comparable at birth, declined by 48 weeks of age in both populations. Early vaccination of HEU infants may limit an initial vulnerability to Hib disease resulting from impaired transplacental antibody transfer. While initial Hib vaccine responses appeared adequate, the confluence of lower antibody avidity and declining Hib-IgG levels in HEU infants by 12 months support Hib booster vaccination at 1 year. Potential immunologic impairments of HEU infants should be considered in the development of vaccine platforms for populations with high maternal HIV prevalence.
Source: Clinical and Vaccine Immunology
DOI: 10.1128/cvi.00356-14
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
Funders: Johns Hopkins University, National Institutes of Health, National Institute of Allergy and Infectious Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Center for Research Resources, National Center for Advancing Translational Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development
Awards: Colorado Clinical and Translational Science Institute (UL1), Mucosal Determinants of HIV Infection of Infants by Breast Milk, Cross-serotype protection against Streptococcus pneumoniae by induction of neutra, FOSTERING PATIENT ORIENTED RESEARCH IN PEDIATRIC NUTRITION, Mucosal Defense vs Transmission of HIV by Breast Milk, Mucosal Immune Ontogeny and Intestinal Microbiota in Infants, Colorado Clinical and Translational Sciences Institute, Colorado Clinical and Translational Science Institute (UL1)
OpenAlex ID: W1983641798