Original StudiesEffect of Early Carriage of Streptococcus pneumoniae on the Development of Pneumococcal Protein-specific Cellular Immune Responses in Infancyvan den Biggelaar, Anita H. J. PhD*; Pomat, William S. PhD†; Phuanukoonnon, Suparat PhD†; Michael, Audrey MT†; Aho, Celestine BSc†; Nadal-Sims, Marie A. BSc*; Devitt, Catherine J. BSc*; Jacoby, Peter A. MSc‡; Hales, Belinda J. PhD§; Smith, Wendy-Anne PhD§; Mitchell, Tim PhD¶; Wiertsema, Selma PhD‖; Richmond, Peter MD, FRACP‖; Siba, Peter PhD†; Holt, Patrick G. DSc, FAA*; Lehmann, Deborah MB BS‡Author Information From the *Division of Cell Biology, Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth WA, Australia; †Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea; Divisions of ‡Population Sciences and §Molecular Biotechnology, Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth WA, Australia; ¶Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, United Kingdom; and ‖School of Paediatrics and Child Health, University of Western Australia, Perth WA, Australia. Accepted for publication October 19, 2011. Anita H. J. van den Biggelaar is currently at Crucell, Innovation and Discovery Lab, PO Box 2048, 2301 CA, Leiden, the Netherlands. Supported by an International Collaborative Project Grant of the Wellcome Trust, UK (071613/Z/03/Z) and the Australian National Health and Medical Research Council (NHRMC) (303123). D.L. received funding from a past (353514) and current NHMRC Program grant (572742) and NHMRC Project Grant (572590). A.H.J. van den Biggelaar is a recipient of a NHRMC R Douglas Wright Biomedical Career Development Award (458780). The authors have no other funding or conflicts of interest to disclose. Address for correspondence: Anita. H. J. van den Biggelaar, Crucell, Innovation and Discovery Lab, PO Box 2048, 2301 CA, Leiden, The Netherlands. E-mail: [email protected]. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.pidj.com). The Pediatric Infectious Disease Journal: March 2012 - Volume 31 - Issue 3 - p 243-248 doi: 10.1097/INF.0b013e318245a5a8 Buy SDC Metrics Abstract Background: The aim of this study was to examine the relationship between nasopharyngeal pneumococcal colonization in early life and the subsequent development of pneumococcal-specific T cell responses. Methods: Pernasal swabs were collected from Papua New Guinean infants at the ages of 1 and 2 weeks (n = 279). At 9 months, in vitro cellular immune responses to choline-binding protein A (n = 132), pneumococcal surface protein A (n = 132), pneumolysin (n = 99), and the pneumococcal conjugate vaccine carrier CRM197 were determined. Responses were compared based on the children's carriage status within the first 2 weeks of life. Results: Within the first 2 weeks of life, 40% of the study children carried Streptococcus pneumoniae. Early carriage was associated with lower interferon-γ and interleukin 10 responses to pneumococcal proteins at age 9 months when children had not received pneumococcal conjugate vaccines during the study period. Conclusions: Early pneumococcal carriage may result in enhanced disease susceptibility and suboptimal vaccine responses by modulating the development of pneumococcal immune responses. © 2012 by Lippincott Williams & Wilkins, Inc.