I am confused about what you are asking here: "suppress my immune system and can cause vaccinations to actually activate the problem that they are designed to prevent" - if you mean the flu shot will make the rotator cuff issue worse, or give you the flu?

According to my primary, if you are on prednisone and get a flu shot, your "immune reaction" to the shot will be suppressed, and it is believed the shot is less effective (since the purpose is to provoke an immune response.) So if the steroid was short-term, she always recommended that I wait to get immunizations until 2 weeks after finishing them. @windwalker, can you weigh in here?

There have been discussions here about using steroids while you have MAC (especially if you are also on the meds) - but for some of us with other issues, it is a matter of weighing the risks and benefits - for me, sometimes they are essential to stop an intractable asthma exacerbation. Or to deal (via injection) with an intolerable arthritis flareup.

When one deals with multiple medical issues, it is really important that each practitioner is fully aware of all that is going on, and even better if you have a good primary caregiver monitoring you. I have found that especially with ortho issues, I need to be an educator about what is or is not OK given my lung issues.

Sue