Undervaccination increases risk of pertussis
Jason Glanz, a researcher with the Institute for Health Research at Kaiser Permanente Colorado in Denver, found that undervaccination with DTaP was associated with increased pertussis risk in children between the ages of three months and 36 months.
"Undervaccination is an increasing trend that potentially places children and their communities at an increased risk for serious infectious disease," the study said.
Glanz and his colleagues looked at children born between 2004 and 2008 who were cared for at eight managed care organizations. Each child with laboratory-confirmed pertussis was matched to four randomly selected control patients.
Of the 72 case patients with pertussis, 47.22 percent were undervaccinated for DTaP, compared to just 22.2 percent of the control patients. Undervaccination was defined as missing any of the four scheduled DTaP doses.
Children were went undervaccinated for three doses of DTaP were 18.56 time more likely to have received a diagnosis of pertussis than children who received the recommended number of doses for their age. Children who did not receive any of the four doses of DTaP were 28.38 times more likely to contract pertussis.