I have found that I just seem to take longer to get over cold, etc. and feel like they hit me harder than before if it happens when I am already dealing with a attack. I try and take better care of myself to avoid getting sick in the first place, if I am or have been on steroids recently then I know that I have to be on my toes because you are less able to fight the germs. I have gotten a flu shot every year since my dx but 2, and got the phnumonia shot the first year. This year being one of those years, I am still recovering from an attack I felt like I was weak enough already w/o the possibility of a reaction to the shot. Plus the shots are in such short supply. I know it is still not too late to get it, and if I feel strong enough now that things have settled down around my house I might check on getting one.
There is no way to totally avoid getting sick, especially with 2 young kids and a dh that works in a hospital. I have never had a cold cause an attack, or at least not that I have related. Worrying about it, or stressing are worse enemy IMO for me than the cold...HTH