Despite widespread pertussis vaccination, outbreaks persist, posing significant risk to infants. This study evaluated whether an accelerated DTaP immunization schedule reduced dosing intervals during a 2003 Oregon outbreak. Using registry data from 5,036 children, mean intervals between doses were compared across counties with and without the recommendation and across time periods. Results showed significantly shorter post-recommendation intervals in counties adopting the accelerated schedule (p<0.0001), with no change in the comparison county. Reductions were consistent across clinic types after adjustment. Findings indicate that accelerated DTaP schedules are feasible and may support outbreak control efforts.
