If a child has a very mild case of chickenpox (for example, only 5 to 10 pox), is s/he immune or should s/he be vaccinated?

A mild case of chickenpox produces immunity to varicella as does a moderate or severe case. A child with a reliable history of chickenpox does not need to receive varicella vaccine. However, if there is any doubt that the mild illness really was chickenpox, it is best to vaccinate the child. There is no harm in vaccinating a child who is already immune.