Effectiveness of Haemophilus influenzae type b vaccination against bacterial pneumonia in Colombia.
OBJECTIVE
To assess the effectiveness of a Hib vaccination program against X-ray defined bacterial pneumonia in children <2 years in Colombia.


METHODS
389 cases of radiologically confirmed pneumonia were recruited from hospitals in Bogota and Medellin, Colombia. Two controls per case, matched on age, sex, and socio-economic level, were selected from children attending child health services at the hospitals where pneumonia cases were admitted.


RESULTS
The risk of having X-ray confirmed pneumonia decreased with each Hib dose received; the vaccine effectiveness was 47% (2-72%) among those receiving one dose; 52% for two doses received, and 55% for three doses. These effectiveness levels remained after adjusting for other factors associated with risk of pneumonia.


CONCLUSIONS
This study indicates that trials may have underestimated the proportion of radiological pneumonia in the under 2s that is due to Hib. This suggests that the impact of the vaccination will be greater than expected if it can be extended to reach the poorest children, who are at the greatest risk.
de la Hoz
Fernando
F
Instituto Nacional de Salud de Colombia, Universidad Nacional de Colombia, Carrera 68D # 40A-50, apto 102 int 5, Bogota, Colombia. fdelahoz@007mundo.com
Higuera
Ana Betty
AB
Di Fabio
Jose Luis
JL
Luna
Mauricio
M
Naranjo
Alberto Gómez
AG
de la Luz Valencia
María
M
Pastor
Desiree
D
Hall
Andrew J
AJ
D016022:Case-Control Studies; D003105:Colombia / Q000453:epidemiology; D006192:Haemophilus Infections / Q000453:epidemiology / Q000517:prevention & control*; D018073:Haemophilus Vaccines / Q000008:administration & dosage*; D019741:Haemophilus influenzae type b / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018410:Pneumonia, Bacterial / Q000453:epidemiology / Q000517:prevention & control*
D018073:Haemophilus Vaccines