Nonspecific (Heterologous) Protection of Neonatal BCG Vaccination Against Hospitalization Due to Respiratory Infection and Sepsis.
BACKGROUND
Bacille Calmette-Guerin (BCG) vaccination has been suggested to have nonspecific beneficial effects in children from developing countries, reducing morbidity and mortality caused by unrelated pathogens.


OBJECTIVE
We aimed to assess the heterologous protective effects of BCG vaccination against respiratory infection (RI) and sepsis not attributable to tuberculosis in children born in Spain.


METHODS
We conducted a retrospective epidemiological study using data from the Official Spanish Registry of Hospitalizations (CMBD-HA) to identify differences in hospitalization rates (HR) in BCG-vaccinated children (Basque Country, where neonatal BCG is part of the immunization schedule and has a 100% coverage) as compared to non-BCG-vaccinated children (from the rest of Spain, where BCG is not used).


RESULTS
A total of 464 611 hospitalization episodes from 1992 to 2011 were analyzed. The HR due to RI not attributable to tuberculosis in BCG-vaccinated children was significant lower compared to non-BCG-vaccinated children for all age groups, with a total preventive fraction (PF) of 41.4% (95% confidence interval: 40.3-42.5; P-value <.001). According to age group, PF was 32.4% (30.9-33.9; P-value <.001) for children under 1 year old, 60.1% (58.5-61.7; P-value <.001) for children between 1 and 4 years old, 66.6% (62.8-70.2; P-value <.001) for children between 5 and 9 years old, and 69.6% (63.3-75.0; P-value <.001) for children between 10 and 14 years old. The HR due to sepsis not attributable to tuberculosis in BCG-vaccinated children under 1 year of age was also significantly lower, with a PF of 52.8% (43.8-60.7; P-value <.001).


CONCLUSIONS
BCG vaccination at birth may decrease hospitalization due to RI and sepsis not related to tuberculosis through heterologous protection.
Translational Pediatrics and Infectious Diseases Section, Pediatrics Department, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela.
María José
MJ
de Castro
Grupo de Investigación en Genética, Vacunas, Infecciones y Pediatría (GENVIP), Instituto de Investigación Sanitaria de Santiago (IDIS), Santiago de Compostela, La Coruña Unidad de Genética, Instituto de Ciencias Forenses y Departamento de Anatomía Patológica y Ciencias Forenses, Facultad de Medicina, Universidad de Santiago de Compostela, Galicia, Spain.
Jacobo
J
Pardo-Seco
Translational Pediatrics and Infectious Diseases Section, Pediatrics Department, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela Grupo de Investigación en Genética, Vacunas, Infecciones y Pediatría (GENVIP), Instituto de Investigación Sanitaria de Santiago (IDIS), Santiago de Compostela, La Coruña.
Federico
F
Martinón-Torres
D000293:Adolescent; D001500:BCG Vaccine / Q000008:administration & dosage* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D056738:Cross Protection; D016021:Epidemiologic Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D064789:Immunity, Heterologous; D008297:Male; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000517:prevention & control*; D012189:Retrospective Studies; D018805:Sepsis / Q000453:epidemiology / Q000517:prevention & control*; D013030:Spain / Q000453:epidemiology; D016896:Treatment Outcome; D014611:Vaccination
D001500:BCG Vaccine
BCG vaccination; children; heterologous effects; nonspecific effects