Here, a cautionary note is sounded. As the number of vaccines in the routine schedule grows, pediatricians and parents alike look to combination vaccines as a way of reducing the number of shots to which children are subjected. Researchers at the University of Florida, however, are expressing concern: According to a study published in the September 2006 issue of Pediatric Infectious Disease Journal, infants between 6- and 10-weeks old who received the five-in-one vaccine that protects against diphtheria, tetanus, pertussis, polio, and hepatitis B concurrently with the PCV7 and Hib vaccine are more likely afterward to run a fever, visit the ED, be subjected to testing (including lumbar puncture), and be given an antibiotic than historical controls who didn't get these vaccines all at the same time.
Over time, researchers found, medical interventions following vaccination decreased, but so did the rate of vaccination for infants younger than 8 weeks. What appears to happen is that pediatricians are avoiding these adverse consequences by delaying the age of immunization-a practice that is risky because it leaves younger infants exposed to such potentially lethal infections as pertussis and could cause families who fail to return to the clinic or office to miss some of the immunizations that their child needs.