Breastfeeding enhances the antibody response to Hib and Pneumococcal serotype 6B and 14 after vaccination with conjugate vaccines

Background: This study was performed in order to investigate the relationship between breastfeeding and the antibody response after vaccination with conjugate vaccines against Hib and pneumococcal diseases. Methods: This was an open non-randomised multi-centre study enrolling 101 healthy Swedish infants. PncCRM was administeredconcomitantly with DTaP/IPV/Hib at 3, 5, and 12 months at separate site. Duration of breastfeeding was calculated for days of almost exclusive as well as of total (any form of) breastfeeding. Results: At 13 months of age 6 out of 83 children did not reach 0.2 mu g/ml against serotype 613, and five of these were breastfed less than 90 days (Fisher's Exact test, P=0.011). Four children did not reach 1 mu g/ml against Hib and all those were breastfed less than 90 days (Fisher's Exact test, P = 0.008). One month after the second dose, at 6 months of age, children breastfed 90 days or more showed significantly higher GMC against serotype 14 (P = 0.003). Conclusion: This study indicates that children exclusively breastfed 90 days or more might get a better serological protection against Hib, and the pneurnococcal serotypes 6B and 14 after vaccination, compared to children less breastfed. (c) 2006 Elsevier Ltd. All rights reserved.