Is a flu cough still contagious after 10 days?

It depends on the individual's immune system and the severity of the flu. The flu is typically most contagious in the first 3-4 days of symptoms, but can be spread up to 7 days after symptoms begin. In some cases, people may be contagious for longer if they have a weakened immune system or a more severe case of the flu. To be safe, it is best to assume that you are contagious until you have been fever-free for at least 24 hours.