Infants too young to receive a vaccination against pneumonia, meningitis and other potentially deadly bacterial infections have experienced a drop in the rate of those diseases, possibly as a result of older children having been immunized. The information is contained in a report by Vanderbilt University researchers, published in the current issue of Journal of the American Medical Association. The study found a 42 percent decline in rates of invasive pneumococcal disease (IPD) caused by the bacteria, streptococcus pneumoniae, among children under 2 months old since a vaccine went on the market in February 2000. Researchers say similar decreases in...