In children of 3 to 36 months of age, undervaccination with the diptheria, tetanus toxoids and acelluar pertussis (DTaP) vaccine appears to be associated with an increased risk of pertussis (whooping cough).
This is according to a study by Jason M. Glanz, Ph.D., of the Institute for Health Research at Kaiser Permanente Colorado, Denver.
"Undervaccination is an increasing trend that potentially places children and their communities at an increased risk for serious infectious disease," according to the study.
Undervaccincation was defined as missing any of four scheduled doses of the DTaP vaccine. Of 72 case patients with pertussis, 34 (47.22 percent) were undervaccinated for DTaP vaccine by the date of pertussis diagnosis compared to 64 (22.2 percent) of the control patients. Children undervaccinated for three or four doses of DTaP vaccine were 18.56 and 28.38 times more likely, respectively, to have received a diagnosis of pertussis than children who were age-appropriately vaccinated, the study reports.
"Undervaccination with DTaP vaccine increases the risk of pertussis among children 3 to 36 months of age," the study concludes.