I saw in one of the vet clinics where they gave vaccinations to birds for new castle disease and infectious bursiti (ND and IB). They also told me that booster shots are given after every 6 months. I am unsure about it being necessary for my cockatiel. Has someone here gotten their birds vaccinated ever? If yes, what are the after effects that can be expected after the vaccine dose? Also, is it okay if I don’t get my bird vaccinated at all?