Children who miss vaccinations at increased risk for whooping cough

Children who miss diphtheria, tetanus toxoid, and acellular pertussis (DTaP) vaccine doses are at more likely to develop whooping cough, according to a study in JAMA Pediatrics.

Jason Glanz, PhD, of Kaiser Permanente Colorado, and colleagues studied the correlation between undervaccination and pertussis in children 3 to 36 months old. They examined data from 8 managed care organizations in the Vaccine Safety Datalink between 2004 and 2010. For purposes of the study, undervaccination for the DTaP vaccine was defined as missing or delaying 1 or more of the first 4 doses by the recommended age.

They found that children who missed 3 doses of the DTaP vaccine were nearly 19 times more likely to develop pertussis than those who received the recommended number of doses. Children who missed 4 doses were 28 times more likely to develop whooping cough.

Last year, more than 41,000 cases of whooping cough were reported to the U.S. Centers for Disease Control and Prevention. Texas and California have reported whooping cough epidemics. Some medical experts attribute the increased incidence to parents who opt not to get their children the DTaP vaccine. Healthcare barriers and medical contraindication have also contributed to the trend.

In the study, 47% of the whooping cough cases belonged to children who were undervaccinated for DTaP. Nearly 30% of the undervaccinated children who developed pertussis are believed to have parents who “intentionally refused or delayed vaccine doses for personal, nonmedical reasons," the study report said.

 Glanz and his colleagues believe 36% of identified pertussis cases identified in the study could have been prevented with on-time vaccination.