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The 13-valent pneumococcal conjugate vaccine compared with the 7-valent pneumococcal conjugate vaccine (PCV7) significantly reduced nasopharyngeal colonization of single serotypes 1, 6A, 6C, 7F, 19A, and 19F, but not serotype 3 or other PCV7 serotypes; serotype 5 had too few events for analysis.Background. The 13-valent pneumococcal conjugate vaccine (PCV13) was licensed to replace the 7-valent pneumococcal conjugate vaccine (PCV7) based on serological noninferiority criteria. To date no randomized PCV13 pediatric trial has included clinical endpoints.Methods. This randomized double-blind trial compared the impact of PCV13 versus PCV7 on nasopharyngeal (NP) colonization and immunogenicity. Healthy infants were randomized (1:1) to receive PCV7 or PCV13 at ages 2, 4, 6, and 12 months; NP swabs were collected at 2, 4, 6, 7, 12, 13, 18, and 24 months, and blood was drawn at 7 and 13 months. Rates of NP acquisition and prevalence, and serotype-specific immunoglobulin G (IgG) concentrations were assessed.Results. The per protocol analysis population included 881 PCV13 and 873 PCV7 recipients. PCV13 significantly reduced NP acquisition of the additional PCV13 serotypes 1, 6A, 7F, and 19A; the cross-reacting serotype 6C; and the common PCV7 serotype 19F. For serotype 3, and the other PCV7 serotypes, there were no significant differences between the vaccine groups. There were too few serotype 5 events to draw inference. The impact on prevalence at predefined time points was similar to that observed with NP acquisition. PCV13 elicited significantly higher IgG responses for PCV13 additional serotypes and serotype 19F, and similar or lower responses for 6/7 PCV7 serotypes.Conclusions. PCV13 resulted in lower acquisition and prevalence of NP colonization than PCV7 did for 4 additional PCV13 serotypes, and serotypes 6C and 19F. It was comparable with PCV7 for all other common serotypes. These findings predict vaccine effectiveness through both direct and indirect protection.Clinical Trials Registration. NCT00508742. [ABSTRACT FROM AUTHOR]

Background. The impact of pneumococcal conjugate vaccination on the prevalence of nasopharyngeal carriage with pneumococci and other bacteria in adults is unknown. The direct effects of the 13-valent pneumococcal conjugate vaccine (PCV13) in community dwelling older adults was investigated as part of the randomized controlled Community Acquired Pneumonia immunization Trial in Adults (CAPiTA). Methods. We determined the carriage of Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis before and 6, 12, and 24 months after vaccination using polymerase chain reaction (PCR)-based methods and conventional cultures of nasopharyngeal and oropharyngeal swab samples in 1006 PCV13 recipients and 1005 controls. Serotyping of the 13 vaccine-type (VT) pneumococci was performed by PCR targeting capsular synthesis genes and Quellung reaction of isolates. Results. Before randomization and based on PCR, 339 of 1891 subjects had nasopharyngeal carriage with any pneumococci (17.9%), and 114 of 1891 (6.0%) carried VT pneumococci. At 6 months after vaccination, VT pneumococcal carriage was significantly lower in PCV13 recipients than in the placebo group (relative risk, 0.53; 95% confidence interval, .35-.80; P = .04). There was no difference between the groups at 12 and 24 months after vaccination. Carriage of non-VT pneumococci, S. aureus, H. influenzae, and M. catarrhalis did not change between groups. Conclusions. In community-dwelling adults aged ≥65 years, a single dose of PCV13 seems to elicit a small and temporary reduction in VT carriage 6 months after vaccination. Neither replacement by non-VT serotypes nor impact on other nasopharyngeal bacteria was observed. [ABSTRACT FROM AUTHOR]

Background. In the randomized controlled Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA), the efficacy of the 13-valent pneumococcal conjugate vaccine (PCV13) against first episodes of vaccine-type community-acquired pneumonia in adults aged =65 years was 46%. The long-term immunogenicity of PCV13 in pneumococcal vaccine-naive older adults was investigated as part of CAPiTA. Methods. We determined the immune responses to PCV13 before and at 1, 12, and 24 months after vaccination in 1006 PCV13 recipients and 1005 controls with 3 age-stratified study participant cohorts. PCV13 serotype-specific opsonophagocytic activity (OPA) titers and immunoglobulin G (IgG) concentrations were determined. Results. Sample collection completeness was at least 93.4% at each time point. In all 3 age categories, a single dose of PCV13 elicited OPA titers and IgG concentrations for all 13 serotypes that were significantly higher than baseline and the corresponding responses in the placebo group at all time points. In the eldest subjects (=80 years of age at vaccination), OPA titers and IgG concentrations remained above baseline and there was no apparent difference in OPA titers and IgG concentrations between those with self-reported comorbidities and healthy older adults. However, the study was not powered to determine statistical significance between different age and comorbidity groups, and thus these results are exploratory. Conclusions. In immunocompetent adults =65 years of age, PCV13 elicits significant increases in OPA titers and IgG concentrations that persist 2 years postvaccination for all 13 serotypes, regardless of age and comorbidity. [ABSTRACT FROM AUTHOR]