TRENTON - (AP) - Call it one of New Jersey's medicalmysteries.

One of the most affluent states in the country, home to morethan a few giants of the pharmaceutical industry, New Jersey alsohas one of the lowest immunization rates in the nation for babiesand toddlers.

The state ranked 42nd last year - and 45th in 2008 - in atelephone survey of parents and pediatricians by the U.S. Centersfor Disease Control and Prevention.

New Jersey's 64 percent rate for giving infants and toddlersrecommended shots for polio, hepatitis B, mumps, measles andrubella and other diseases last year was well below the nationalaverage of nearly 71 percent, and the lowest in the Northeast.

Nobody knows for sure why New Jersey's vaccination rate hasslipped so low, but public health professionals and pediatricianshave seen it building for several years.