IMM250H1 Lecture Notes - Lecture 10: Flu Season, Upper Respiratory Tract Infection, 1918 Flu Pandemic
Document Summary
What is influenza: flu refers to infection with influenza virus, an acute upper respiratory infection, symptoms include; fever, cough, muscle aches, flu more severe in old, very young, and those with chronic conditions. Influenza types: there are three kinds of influenza virus, influenza a: regular outbreaks and occasional pandemics. Different subtypes and different strains within subtypes: influenza b: regular outbreaks. Why do we constantly need new vaccines: antigenic shift: genes are re-assorted in reservoir to make a complexly new virus, antigenic drift: many small mutations due to error prone polymerase. Infection is different for na ve individual vs previously infected or vaccinated individual: na ve: both the virus and the immune response to infection cause damage and symptoms and viral spread. Inoculated: pre-existing antibodies stop the virus before it infects epithelial cells no illness and no spread: takes several days to mount a t cell response but after a while it will eventually clear a non-lethal infection.
