Several people I know were sick with a flu for a month or more in the fall of 2019 or early pre-pandemic in early 2020. Some had viral pneumonia. It seems like a lot of people had similar experiences. My wife was very sick after a trip to Philadelphia in Fall 2019. She sounded like a bullfrog and had a cough for nearly 2 months after a week and a half in bed. I think it was when nursing homes had people dying at such high rates that it was accepted to be something new and dangerous.