influenza
"I have flu many times over the last half century, but last year, even after flu vaccine, was the absolute worst. This year symptoms hit me like a ton of bricks on a Friday afternoon: pulse of 120, fever of 102, terrible chills and body aches. I headed straight to a clinic (doc's office was closed) and got a prescription for Tamiflu, which I started immediately. When I awoke the next day my symptoms were much better. I still had the flu, but a mild case."