270 REVISTA DE INVESTIGACIÓN CLÍNICA Contents available at PubMed www.clinicalandtranslationalinvestigation.com REVISTA DE INVESTIGACIÓN CLÍNICA Rev Inves Clin. 2017;69:270-273 Pneumococcal Conjugate Vaccine and Pneumonia Prevention in Children with Congenital Heart Disease Fortino Solórzano-Santos 1 , Lilia Espinoza-García 2 , Glorinella Aguilar-Martínez 3 , Luisa Beirana-Palencia 4 , Gabriela Echániz-Avilés 5 and Guadalupe Miranda-Novales 6 * 1 Evidence-based Medicine Research Unit, Hospital Infantil de México, “Federico Gómez”, Secretaría de Salud, Mexico City; 2 Department of Pediatrics, Hospital Regional # 72 Tlalnepantla, Instituto Mexicano del Seguro Social, Tlalnepantla, Mexico City; 3 Centro Médico de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jal.; 4 Department of Cardiology, Hospital Ángeles, Clínica Londres, Mexico City; 5 Instituto Nacional de Salud Pública, Cuernavaca, Mor.; 6 Hospital Epidemiology Research Unit, Health Research Coordination, IMSS, Mexico City. Mexico ABSTRACT Background: A successful strategy to prevent Streptococcus pneumoniae infections is the administration of pneumococcal conjugate vaccines (PCVs). Objective: To analyze the effectiveness of the 7- and 13-valent PCV for the prevention of all-cause pneumonia. Materials and Methods: A retrospective cohort of children younger than 5 years of age, with congenital heart disease (CHD) and different vaccination schedules, was analyzed. History of vaccination was confirmed with verifiable records. The outcome measure was all-cause pneumonia or bronchopneumonia. Protocol was approved by the Institutional Review Board. For comparisons, we used inferential statistics with Chi-square and Fisher’s exact test; a p ≤ 0.5 was considered statistically significant. Relative and absolute risks reduction and number needed to treat were also calculated. Results: A total of 348 patients were included: 196 with two or more doses of PCV (considered the vaccinated group), and 152 in the unvaccinated group. There was a statistically significant difference for pneumonia events (p < 0.001) between the vaccinated (26/196) and unvaccinated (51/152) groups. The relative risk reduction was 60.5%, and the absolute risk reduction, 20.3%. There were no differences between patients who received two, three or four doses. The number needed to vaccinate to prevent one event of pneumonia was 5 children. Conclusions: At least two doses of PCV in children with CHD reduced the risk of all-cause pneumonia. Key words: Congenital heart disease. Pneumonia. Streptococcus pneumoniae. Vaccine. INTRODUCTION In developing countries, invasive pneumococcal disease remains as one of the main causes of morbidity and mortality in children younger than 5 years, with the highest incidence among children under 18 months of age. Streptococcus pneumoniae is a major bacterial pathogen responsible for a wide spectrum of invasive diseases (pneumonia, bacteremia, and meningitis), as well as non-invasive diseases. In addition to young chil- dren, patients with high risk are those with a variety of underlying and chronic conditions (e.g., children with surgical or functional asplenia, organ transplant, AIDS, primary immunodeficiencies, chronic heart, lung, liver or renal disease, and with cerebrospinal fluid leak) 1,2 . A successful global strategy to prevent infections by S. pneumoniae has been the application of pneu- mococcal conjugate vaccines (PCVs) 3,4 . In Mexico, the heptavalent PCV was available in 2006 and first administered to a selected high-risk group of children. It was included in 2008 to the National Immunization Program. In private medicine, three doses plus a booster (at 2, 4, 6, and 12 months) were administered, Corresponding author: *Guadalupe Miranda-Novales Unidad de Investigación en Epidemiología Hospitalaria Coordinación de Investigación en Salud Instituto Mexicano del Seguro Social Av. Cuauhtémoc, 330 Col. Doctores, Del. Cuauhtémoc C.P 06720, Ciudad de México, México E-mail: guadalupe.mirandan@imss.gob.mx Received for publication: 03-04-2017 Approved for publication: 30-05-2017 doi: 10.24875/RIC.17002241 PERMANYER ORIGINAL ARTICLE No part of this publication may be reproduced or photocopying without the prior written permission of the publisher. © Permanyer Publications 2017