[Flu vaccine effectiveness: a metaanalysis].
BACKGROUND
Seasonal influenza is a disease of great interest in public health due to its high rates of infection and big costs, especially in high-risk population. This situation has motivated studies related to development of control measures necessary to mitigate its impact. Immunization constitutes a key role in providing the necessary interventions; however, little information is available about its effectiveness as public health measure in tropical countries.


OBJECTIVE
The vaccine effectiveness was evaluated by means of published results in the scientific literature.


METHODS
Meta-analysis techniques were used to summarize the results of epidemiological analytical studies. A critical evaluation was undertaken for each study to identify the potential biases and methodological limitations.


RESULTS
Two hundred and fifty-seven relevant studies were located, of which 28 were included in the analysis. The pooled estimator of the vaccine effectiveness for hospitalization was 0.74 [95% CI 0.68-0.81] in older adults (65 years and older) in cases-control studies. For cohort studies, the obtained estimator was 0.80 [95% CI 0.68-0.91].


CONCLUSIONS
Other conclusions were analyzed, and in general, a protective effect was demonstrated in the vaccine. About 1,200,000 were involved, 530,000 of them were vaccinated. Geographically, the analyzed studies came from developed countries in Europe, America and Asia.
Moreno
José
J
Grupo de Epidemiología, Subdirección de Investigaciones, Instituto Nacional de Salud, Bogotá D.C., Colombia. josemorenomontoya@gmail.com
De la Hoz
Fernando
F
Rico
Alejandro
A
Cotes
Karol
K
Porras
Alexandra
A
D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D005069:Evaluation Studies as Topic; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control*; D008297:Male
D007252:Influenza Vaccines