Isn’t there a horror/apocalypse story that starts out with a cold type virus escaping a secret Govt lab and killing off millions? You always knew when the virus had infected someone cause they developed a slight cough.
“The Stand” scared the crap out of me when I read it back when.
Maybe Stephen King’s “The Stand”?
That had like 99% of the world’s population dying from a genetically engineered “superflu” that escaped from a government lab.