What's the probability that a child under one year old will catch chicken pox?

Varies : If the community has a good vaccination rate the chance of exposure is minimized. The vaccination is generally given first at 1 yr or later because earlier administration is not as dependable for providing long term protection. Avoiding unvaccinated kids or exposure to adults with shingles can help decrease risk of the disease.By the time a kid has spots, they have already been contagious > 24hrs.