Q: What is the infectivity period of Herpes Zoster? Do infants below 6 months have adequate immunity (gained from mother) to protect themselves from Chicken pox?

A:Herpes Zoster is infectious if it is associated with vesicular lesion. Till the time scabs have formed and dried these lesions are infectious. Infants do have immunity against chickenpox if the mother before pregnancy had developed chickenpox or got the vaccine against chickenpox and she has viable antibodies in her blood. These antibodies are passed on to the foetus and are protective even upto one year.