The immunity bug bites ; India becomes a hot market for optional vaccines.

The paediatrician shrugged: "It's your choice, if you don't wantthe chicken pox vaccine for your daughter. But remember, one day shewill get married and if she has the pox when she is carrying, thechild could be born with brain damage." And what about the son, thefather voiced his and his wife's concern? "Well, you know whatcompetition is like today...what if he has pox before a major exam?"

Choices, choices. The parents knew a bout of chicken pox builtmore immunity in a child than any vaccine. But, a damaged brain?They plumped for the optional vaccine. Multiply that decision 26million times - that's the number of newborns in India every year -and it is easy to see why Big …