Do they not offer free flu jabs to all medical people these days? If not they should. I know this wouldn't have helped in the case of a severe cold -which can lay you up for a few days- but at least it would avoid the risk of the real thing too. (Which is always a risk when your immune system is still down after a bad cold etc). The civil service also operated the same 'warning' system over sick days when I was there. Considering how many people were genuinely sick with stress related problems (often due to staffing levels, etc) -this often just made the problem worse.