(See the article by El Sahly et al, on pages 703–12.) Influenza causes significant morbidity and mortality with an estimated 36 000 attributable deaths in the United States annually [1]. Human immunodefi-ciency virus (HIV) infection, specifically , advanced disease (CD4 count ,200 cells/lL), has been associated with excess morbidity and mortality [2]. With the use of combination antiretroviral ...