Children aged 3 to 36 months who do not receive the recommended doses of diphtheria-tetanus toxoids-acellular pertussis vaccine are at an increased risk for pertussis infection, according to results of a study released this week.
“Although the results are not surprising, they do highlight two important points. One, while the effectiveness of the DTaP vaccine wanes over time, it is highly effective during infancy. Two, the results stress the importance of vaccinating according to the ACIP schedule,” study researcher Jason M. Glanz, PhD, assistant professor of epidemiology, Colorado School of Public Health, Denver, told Infectious Diseases in Children.
Jason M. Glanz
The study involved children born between 2004 and 2008 at eight managed care organizations. Each of the 72 children with laboratory-confirmed pertussis was randomly matched to four patients in the control group (n=288).
Undervaccination was defined as missing any of four scheduled doses of the DTaP vaccine. Of 72 case patients with pertussis, 34 (47%) were undervaccinated for DTaP vaccine by the date of pertussis diagnosis compared with 64 (22%) of patients in the control group. Children who missed three or four doses of DTaP vaccine were 18.56 and 28.38 times more likely, respectively, to be diagnosed with pertussis than children who were age appropriately vaccinated, the study reports.
Disclosure: This study was funded through a subcontract with America's Health Insurance Plans under contract from the CDC. The researchers report no relevant financial disclosures.