Key Message
Pediatric asthma patients showed enhanced signs of airway hyperresponsiveness at 1 versus 3 months post hospital discharge. This study also used mouse models of asthma-disposed mice to test whether pandemic or seasonal strains of the influenza could enhance airway hyperresponsiveness. The pandemic A(H1N1)pdm09 strain significantly worsened airway inflammation and function compared to the seasonal flu, although these effects were limited to the acute phase at 7 days post infection. By 10 days post infection, the resolution phase was reached and differences between groups of mice infected with different influenza virus strains were negligible. In summary, our study indicates that acute influenza infection can exacerbate asthma phenotypes, particularly pandemic strains that cause severe immunopathology.