I am a 57-year-old kidney-transplant recipient on cyclosporine, Imuran, prednisone and various other medicines. My grandson just had a vaccination for the prevention of chickenpox. Should I avoid contact with him? If so, for how many days?

Maryann

The varicella vaccine can induce a mild infection because the vaccine contains live, attenuated (weakened) virus. It is possible to pass the virus to others after being vaccinated. This is actually more of a risk if the person receiving the vaccine is immune-suppressed, as occurs with cancer or drugs such as Imuran (generic name azathioprine) and prednisone (trade name Deltasone). Also, if a person develops a chickenpox-like rash after receiving the vaccine, he or she is probably more likely to transmit the virus to others. In fact, the U.S. Centers for Disease Control recommend that people who develop a rash after getting the vaccine avoid those with an immune-suppressing condition.

In your case, there are a few points to make. First, you are only susceptible to varicella if you have never had it before. If you had chickenpox as a child, then you are essentially immune to it now, regardless of any immune-suppression you have today. That applies to most patients with immune deficiency. For example, if a patient with AIDS has had chickenpox in the past, he or she should not be able to get it again and thus does not really need to avoid those with the disease.

If you have not had chickenpox before, or if you are not sure, it is probably too late to get the blood test that detects antibodies to varicella. (A positive antibody test would mean that you were immune and could not catch chickenpox from your grandson.) If you do not think you are immune, then you should definitely avoid your grandson if he develops any rash. Avoid him until his rash crusts over entirely.

Whether you should avoid him even if he does not develop a rash is hard to say. He could still possibly transmit the virus, and the risk to you would be low but probably not zero. To my knowledge, there are no data concerning when such a person would be most likely to pass the virus, but the incubation period for natural varicella is between 10 and 21 days after infection. That would be the period after vaccination I would be most concerned about.