Alvaro Díaz, Núria Soldevila, Magda Campins, Cristina Esteva, Angela Domínguez, Fernando A. Moraga-Llop, Carmen Muñoz-Almagro, Gemma Codina, Mariona Fernández de Sevilla, Ana María Planes, Anna Solé-Ribalta, Pilar Ciruela, Sergi Hernández, Luis Salleras, Juan José García-García, Conchita Izquierdo, Sebastià González-Peris, Johanna Martínez-Osorio, Sonia Uriona, Universitat de Barcelona, Institut Català de la Salut, [Domínguez Á, Soldevila N] Departament de Medicina, Universitat de Barcelona, Barcelona, Spain. CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain. [Ciruela P] CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain. Agència de Salut Pública de Catalunya, Generalitat de Catalunya, Barcelona, Spain. [Hernández S, Izquierdo C] Agència de Salut Pública de Catalunya, Generalitat de Catalunya, Barcelona, Spain. [García-García JJ] CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain. Malalties Prevenibles amb vacunes, Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain. Hospital Sant Joan de Déu Barcelona, Universitat de Barcelona, Barcelona, Spain. [Moraga-Llop F, González-Peris S, Codina G, Planes AM] Vall d'Hebron Hospital Universitari, Barcelona, Spain. [Campins M, Uriona S] Vall d'Hebron Hospital Universitari, Barcelona, Spain. Grup de Recerca en Epidemiologia i Salut Pública, Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain, and Vall d'Hebron Barcelona Hospital Campus
Estudis de control de casos; Pneumònia; Vacunació i immunització Estudios de casos y controles; Neumonía; Vacunación e inmunización Case-control studies; Pneumonia; Vaccination and immunization Background The 13-valent pneumococcal conjugate vaccine (PCV13) was licensed based on the results of immunogenicity studies and correlates of protection derived from randomized clinical trials of the 7-valent conjugate pneumococcal vaccine. We assessed the vaccination effectiveness (VE) of the PCV13 in preventing invasive pneumococcal disease (IPD) in children aged 7–59 months in a population with suboptimal vaccination coverage of 55%. Methods The study was carried out in children with IPD admitted to three hospitals in Barcelona (Spain) and controls matched by hospital, age, sex, date of hospitalization and underlying disease. Information on the vaccination status was obtained from written medical records. Conditional logistic regression was made to estimate the adjusted VE and 95% confidence intervals (CI). Results 169 cases and 645 controls were included. The overall VE of ≥1 doses of PCV13 in preventing IPD due to vaccine serotypes was 75.8% (95% CI, 54.1–87.2) and 90% (95% CI, 63.9–97.2) when ≥2 doses before 12 months, two doses on or after 12 months or one dose on or after 24 months, were administered. The VE of ≥1 doses was 89% (95% CI, 42.7–97.9) against serotype 1 and 86.0% (95% CI, 51.2–99.7) against serotype 19A. Serotype 3 showed a non-statistically significant effectiveness (25.9%; 95% CI, -65.3 to 66.8). Conclusions The effectiveness of ≥1 doses of PCV13 in preventing IPD caused by all PCV13 serotypes in children aged 7–59 months was good and, except for serotype 3, the effectiveness of ≥1 doses against the most frequent PCV13 serotypes causing IPD was high when considered individually. This work was supported by the Plan Nacional I+D+I, ISCIII – Subdirección General de Evaluación y Fomento de la Investigación Sanitaria (Projects PI 11/02081, PI 11/2345) and cofounded by Fondo Europeo de Desarrollo Regional (FEDER) and AGAUR (Grant 2014 SGR 1403).