I'll re-read the article to see if it says, but what's the scoop on vaccinating a child that has already had a mild case of chickenpox? Are there contraindications due to the potential for shingles?
Was the child ever vaccinated? Are there any unusual factors in the child's medical history including the pregnancy, such as the mother having chicken pox while pregnant? The latter situation is the only situation that I know of where children get shingles, which is reactivation of the virus, usually starting about five decades later in otherwise healthy adults. I think they won't have any good data for quite a while, since they started using the vaccine only 9 years ago.