RT Book, Section A1 Rac, Hana A1 Bookstaver, P. Brandon A1 Sutton, S. Scott A2 Sutton, S. Scott SR Print(0) ID 1158314854 T1 Influenza T2 McGraw-Hill's NAPLEX® Review Guide, 3e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781260135923 LK accesspharmacy.mhmedical.com/content.aspx?aid=1158314854 RD 2024/04/23 AB Influenza is a viral infection that attacks your respiratory system (nose, throat, and lungs) causing significant morbidity and mortality, particularly among children and elderly. Influenza occurs at any time during the year, but the highest rates occur between December and March. Influenza A and B are the two types of influenza viruses and influenza A is further categorized into subtypes based upon two surface antigens (hemagglutinin and neuraminidase). Immunity to influenza occurs from antibody development directed at the surface antigens.