Vaccine 21 (2003) 1562–1571 Symposium Proceedings Pneumococcal conjugate vaccines: proceedings from an Interactive Symposium at the 41st Interscience Conference on Antimicrobial Agents and Chemotherapy Stephen I. Pelton a , Ron Dagan b , Beverly M. Gaines c , Keith P. Klugman d , Dagna Laufer d , Katherine O’Brien e , Heinz-J. Schmitt f,∗ a Boston University School of Medicine, Boston Medical Center, Boston, MA, USA b Ben-Gurion University, Pediatric Infectious Disease Unit, Soroka University Medical Center, Beer-Sheva, Israel c University of Louisville School of Medicine, Louisville, KY, USA d Global Medical Affairs, Wyeth Pharmaceuticals, St. Davids, PA, USA e School of Hygiene and Public Health, Center for American Indian and Alaskan Native Health and Department of Pediatrics, Johns Hopkins Hospital, Baltimore, MD, USA f Department of Pediatrics, Pediatric Infectious Diseases, Center for Preventive Pediatrics, Johannes Gutenberg University, Langenbeckstr. 1, 55101 Mainz, Germany Received 30 September 2002; accepted 30 October 2002 Abstract Globally, Streptococcus pneumoniae is a leading cause of invasive and noninvasive disease in infants and young children. The emer- gence of antibiotic-resistant strains has increased interest in prevention through immunization. Currently, the only available conjugate pneumococcal vaccine is a seven-valent formulation, PNCRM7. This paper presents excerpts from a symposium that provided an update of ongoing surveillance data and clinical trials evaluating pneumococcal conjugate vaccines. The topics addressed included: (1) PNCRM7 postmarketing safety data; (2) the impact of PNCRM7 in premature infants; (3) the direct and indirect effect of pneumococcal conjugate vaccines on colonization; (4) the effect of pneumococcal conjugate vaccines on replacement disease and the rate of resistance among replacement serotypes; (5) the current recommendations for the use of PNCRM7; and (6) the potential impact of conjugate vaccines in Europe and the Asia-Pacific region. © 2002 Elsevier Science Ltd. All rights reserved. Keywords: Acute otitis media; Pneumococcal conjugate vaccines; Streptococcus pneumoniae 1. Introduction Pneumococcal infections cause substantial morbidity and mortality worldwide, especially in young children [1]. While antibiotics have been used successfully to treat pneu- mococcal infections, increasing antibiotic resistance has complicated disease management [2–8]. Thus, an increased interest in prevention through pneumococcal immunization has emerged. The 23-valent pneumococcal polysaccharide vaccines have been made available by various manufacturers worldwide and are effective in individuals 2 years of age or older; however, because they elicit a T-cell-independent re- sponse, these vaccines are not effective in children younger ∗ Corresponding author. Tel.: +49-6131-175033; fax: +49-6131-1747-5033. E-mail address: schmittj@kinder.klinik.uni-mainz.de (H.-J. Schmitt). than 2 years of age [9]. Additionally, the polysaccharide vaccines do not prime for an anamnestic response and have no effect on nasopharyngeal carriage of pneumococcal strains or otitis media [9]. Pneumococcal vaccines conju- gated to protein carriers are available or in development, and due to their technology, elicit a T-cell-dependent response, making them immunogenic and efficacious in children younger than 2 years of age [10,11]. Currently, the only available conjugate pneumococcal vaccine is a seven-valent formulation (4, 6B, 9V, 14, 18C, 19F, and 23F), which is conjugated to a nontoxic diphtheria variant (CRM 197 ) (PNCRM7; Prevnar ® , US; Prevenar ® , internationally; Wyeth). In clinical trials to date, pneumococcal conjugate vaccines have been shown to induce high concentrations of serum an- tibody [12,13] and reduce nasopharyngeal carriage of vac- cine serotypes [14–22]. PNCRM7 has also been shown to be 0264-410X/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII:S0264-410X(02)00681-3