The aim of this double blind randomized controlled trial is to compare the clinical efficacy and safety of celecoxib combined with neuraminidase inhibitors in patients with severe influenza A infection. The hypothesis of this study is that treatment of severe influenza A infection with celecoxib will reduce mortality. The primary outcome to be assessed will be the 28-days mortality rate from hospitalization. The secondary outcomes to be assessed will be safety of the treatment, duration of intensive care, duration of ventilatory and oxygen support, the viral load and cytokine change.
