RT Book, Section A1 Winders, Hana R. A2 Sutton, S. Scott SR Print(0) ID 1179734518 T1 Influenza T2 McGraw Hill’s NAPLEX® Review Guide, 4e YR 2020 FD 2020 PB McGraw-Hill Education PP New York, NY SN 9781264258062 LK accesspharmacy.mhmedical.com/content.aspx?aid=1179734518 RD 2024/04/24 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.