Q: If a person has had chicken pox in infancy or early childhood, but does not remember it, is it still safe to go ahead and get oneself immunised against chicken pox by means of Varilrix? Further, is it possible that since the germs are being introduced into the body during immunisation against chicken pox, a person may develop Shingles without first suffering from chicken pox? I am a 35 year old male, and I assume that I have not had chicken pox during my childhood.

A:It is safe to be immunised against chickenpox even though you do not recall having the disease as a child. The uncommon situations in which one should not to be vaccinated are the same as for anyone else - mainly any condition, such as HIV infection or cancer treatment, that would impair ones ability to control infection. Sometimes chickenpox is mild enough, especially in young children, that might not be recognized as such. Most adults have in fact had chickenpox as children, especially if they were around lots of other children when they were young. You can have a blood test for antibodies against chickenpox, indicating previous infection, and if they are present, you need not be vaccinated. But testing is not essential before vaccination. Although the chickenpox (varicella) vaccine is made of live virus that has been weakened, and one might imagine that it could cause Shingles, in fact this has not been shown to be the case and is not a reason for avoiding chickenpox vaccination.