Serotype Distribution of S. pneumoniae Community Acquired Pneumonia (CAP) in Adults in the Netherlands in the CAPiTA (Community-Acquired Pneumonia Immunization Trial In Adults) Study Period
Methods: In this double-blind, placebo-controlled, study, 84,496 immunocompetent adults aged ≥65 years were vaccinated with a single dose of PCV13 or placebo. The study continued until a pre-specified number of VT-CAP cases had occurred; episodes were identified using a PCV13-serotype-specific urinary antigen detection assay or by isolation of VT pneumococcus from a sterile site. Seven-valent pneumococcal conjugate vaccine (PCV7) was introduced for Dutch infants in 2006 as a 3+1 schedule, replaced by ten-valent pneumococcal conjugate vaccine (PCV10) in 2011; vaccination uptake is ~95%. Serotype distribution of PCV13 serotypes overall, and among placebo recipients (as a surrogate for the 65+ Dutch population) is described for each study year.
Results: All 13 PCV13 serotypes were confirmed among first episodes of VT-CAP (per-protocol population) over the duration of the study; most frequently identified were serotypes 1, 3, 7F, 19A. There were 4 episodes of PCV7-type CAP in placebo recipients in 2009, 3 in 2010, 6 in 2011, 2 in 2012, and 3 in 2013. For the additional serotypes in PCV13, there were 12, 17, 18, 16, and 9 episodes in 2009, 2010, 2011, 2012, and 2013 (7 months only), respectively.
Conclusion: Despite an infant NIP recommending PCV10, the most frequently observed serotypes in CAP among CAPiTA subjects included 1 and 7F. PCV7 serotypes persisted and their prevalence remained stable over the study. Furthermore, there was no evidence of a change in the frequency of the additional PCV13 serotypes.
Pfizer Vaccine Clinical Research: Employee and Shareholder, Salary
M. Bolkenbaas, None
C. Webber, Pfizer Vaccines Clinical Research: Employee and Shareholder, Salary
S. Gault, Pfizer Vaccine Clinical Research: Employee and Shareholder, Salary
S. D. Patterson, Pfizer Vaccines Clinical Research: Employee, Salary
W. Gruber, Pfizer Vaccines Clinical Research: Employee and Shareholder, Salary
D. E. Grobbee, Pfizer Vaccines Clinical Research: Investigator, Research grant
M. Bonten, Pfizer Vaccines Clinical Research: Investigator, Research grant