What causes antigenic shift?

May 1, 2023 ... Infectious Agent. Influenza is caused by infection of the respiratory tract with influenza viruses, RNA viruses of the Orthomyxovirus genus. What Causes Influenza? Influenza is caused by several different viruses that are in the influenza family. Each year, flu season is defined by a few ... Influenza seasonality: underlying causes and modeling theories. J Virol. 2007 Jun;81(11):5429-36. doi: 10.1128/JVI.01680-06. Epub 2006 Dec 20. Influenza (flu) is a highly contagious viral infection of the respiratory tract that can cause severe illness and life-threatening complications (including ... Influenza (or “flu”) is a respiratory infection caused by influenza virus. Influenza outbreaks happen every year, usually between November and April. Mar 7, 2025 ... Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. Its severity can vary from mild to ... Feb 12, 2018 ... We all know the symptoms of influenza infection include fever, cough, sore throat, muscle aches, headaches and fatigue. But just what causes all the havoc? Feb 28, 2024 ... The flu is caused by flu viruses that spread from person to person. When someone with the flu coughs, sneezes, or talks, they spray tiny ... Feb 4, 2025 ... Pneumonia symptoms and causes · Bacterial pneumonia. · Viral pneumonia. Various viruses can cause this type, including the influenza virus, and it ... What causes influenza? · Through the air, in droplets that an infected person spreads through a cough or sneeze · Through touching things that infected people ...