Amit,
It can depend on the individual. Some TKIs (to some people) can suppress their blood counts a bit. For example my white cell count is always quite low. Not dangerously low or anything, but often is below the expected "normal" range.
So whilst I don't worry too much about my immune system, I do try to take extra care in terms of using alcohol hand gel before handling food, for example, especially if somewhere that might not have great food hygiene.
To give you a real-life example, I am currently dealing with a bacterial infection which my doctor has prescribed antibiotics that are stronger than they would give a non-CML patient. In fact they might not have needed to give any at all to most people as their body may have fought off the infection itself.
That's just my opinion. I think it's good to be wary of infection more than a non-CML patient but it's easy to go overboard too.
David.