Pertussis risk grows as time since last DTaP dose increases

A recent study determined that children have an increased risk of pertussis as the time since the last dose of the diphtheria, tetanus and acellular pertussis vaccine lengthens.

Lara K. Misegades of the Centers for Disease Control and Prevention and her colleagues conducted a study to evaluate the connection between pertussis and the receipt of all five DTaP doses. The researchers found that children who received their last dose of the vaccine within 12 months were much less likely to contract the disease than children who had the final vaccine dose more than 60 months in the past, Science Daily reports.

"The increasing incidence of pertussis, changing epidemiology, and demonstrated decline in the estimated DTaP (vaccine effectiveness) over time have raised concerns about the current U.S. pertussis vaccine program and may prompt consideration of alternative schedules," the authors said, according to Science Daily. "Ultimately, improved control of pertussis may require a vaccine that provides longer duration of protection or differently affects transmission in the community."

The estimated relative decline in vaccine efficiency was 27.4 percent when comparing children who received their final dose within the last 12 months versus children who received it more than 60 months ago.

Children with pertussis were found to have an 89 percent lower chance of having received all five DTaP doses compared to children who received all the doses, Science Daily reports.