influenza
"Flu came on quickly on Saturday.  Docs office was closed and I was sick all day Sunday and called first thing Monday morning and they got me in for an appointment.  Fever was 102 with chills, headache, etc.  I got the flu shot several months prior but it covered the wrong strain which is the one that hit me.  Doc gave me prescription for Tamiflu which I started right away.  I still stayed home from work Monday and Tuesday but felt better on Wednesday, still a bit sluggish though.  Did this help shorten the duration? Not certain but I think it definitely did help."