Both my little guys were vaccinated against chicken pox around age one , and I remember because I had to pay for it at that time, though now it is covered by our provincial plan. Started getting memos that it was going around the school. Then little brother William (no DMD) caught it, though it was a mild case. But now caught in great fun decinding what to do with Simon, immunosuppressed due to Deflazacort, and trying to figure out when 'exposure' occurred. Was it at school 2 or 3 weeks ago, only from his brother 10 days ago, or this morning, or not at all? First medical team was not very concerned and was not going to do anything, then they were going to give him immunoglobulins, but finally decided on Acyclovir for 7 days, with strict isolation (heavy duty mask, negative pressure room, etc) while in a hospital or medical context for the other immunosuppressed patients, but walking around at school and in the general community without any precautions what so ever.