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Kinetics of pneumococcal antibodies among HIV-exposed, uninfected infants in Botswana
Emilie A Uffman1, Shuk Hang Li2, Jui-Lin Chen1
1Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC, USA.
Insights
HIV-exposed, uninfected infants show good initial response to pneumococcal conjugate vaccine (PCV-13), but antibody levels wane by 12 months. A booster dose may be needed to maintain protection against invasive pneumococcal disease.
Area of Science:
- Immunology
- Pediatrics
- Infectious Diseases
Background:
- * Streptococcus pneumoniae causes severe childhood infections.
- * HIV-exposed, uninfected (HEU) infants have higher invasive pneumococcal disease risk than HIV-unexposed, uninfected (HUU) infants despite vaccination.
- * The immunogenicity of 13-valent pneumococcal conjugate vaccine (PCV-13) in HEU versus HUU infants requires comparison.
Purpose of the Study:
- * To compare the immunogenicity of PCV-13 in HEU and HUU infants.
- * To assess antibody concentrations and protective levels against pneumococcal serotypes post-vaccination.
Main Methods:
- * Prospective cohort study of 134 mother-infant dyads in Botswana.
- * Infants received PCV-13 at 2, 3, and 4 months.
- * IgG antibodies specific to vaccine serotypes measured at birth, 5, and 12 months.
Main Results:
- * At birth, HEU infants had lower antibody concentrations to serotypes 5 and 19A compared to HUU infants.
- * Over 80% of both HEU and HUU infants achieved protective antibody levels after PCV-13 vaccination.
- * Antibody concentrations significantly declined between 5 and 12 months, with fewer than half having protective levels for several serotypes at 12 months.
Conclusions:
- * Both HEU and HUU infants mount protective antibody responses to PCV-13.
- * Substantial waning of antibody concentrations by 12 months suggests a need for a PCV-13 booster dose.
- * Maintaining protective pneumococcal antibody levels in older infants may require a booster vaccination strategy.
Background:
Streptococcus pneumoniae is a leading cause of severe infections among children. Despite vaccination, HIV-exposed, uninfected (HEU) children have a higher incidence of invasive pneumococcal disease than HIV-unexposed, uninfected (HUU) children. We sought to compare the immunogenicity of 13-valent pneumococcal conjugate vaccine (PCV-13) in HEU and HUU infants.
Methods:
We conducted a prospective cohort study of 134 mother-infant dyads in Botswana. Infants received PCV-13 doses at 2, 3, and 4 months through routine clinical care. We measured IgG antibodies specific to vaccine serotypes in sera collected from infants at 0, 5, and 12 months of age. We calculated the proportion of infants with protective IgG levels (≥0.35 µg/mL) to specific pneumococcal serotypes.
Results:
At birth, fewer than half of infants had protective IgG levels to serotypes 1 (38%), 3 (46%), 4 (33%), 5 (23%), 6B (40%), 7F (44%), 9 V (44%), and 23F (46%). Compared to HUU infants (n = 97), HEU infants (n = 37) had lower antibody concentrations at birth to serotypes 5 (p = 0.046) and 19A (p = 0.008) after adjustment for maternal age and infant birth weight. More than 80% of HEU and HUU infants developed protective antibody levels to each of the 13 vaccine serotypes following PCV-13 vaccination. Median concentrations of antibodies to pneumococcal serotypes declined by 55-93% between 5 and 12 months of age, with fewer than half of infants having protective antibody levels to serotypes 1 (47%), 3 (28%), 9 V (44%), 18C (24%), and 23F (49%) at 12 months of age.
Conclusions:
Both HEU and HUU infants developed protective antibody responses to PCV-13 administered in a 3 + 0 schedule. However, antibody concentrations to many pneumococcal serotypes waned substantially by 12 months of age, suggesting that a PCV-13 booster dose in the second year of life may be needed to maintain protective pneumococcal antibody levels in older infants and young children.
