Pediatric hospital admissions from influenza A (H1N1) in Brazil: effects of the 2010 vaccination campaign.

lIn 2009, the influenza A (H1N1) virus spread rapidly around the world, causing the first pandemic of the 21st Century. In 2010, there was a vaccination campaign against this new virus subtype to reduce the morbidity and mortality of the disease in some countries, including Brazil. Herein, we describe the clinical and epidemiological characteristics of patients under 19 years of age who were hospitalized with confirmed influenza A (H1N1) infection in 2009 and 2010.