- Under-, unvaccinated children have elevated pertussis risk vs fully diphtheria-tetanus-acellular pertussis (DTaP)-vaccinated children.
- Both un/under and fully vaccinated children are at increased risk during pertussis epidemics, the latter due to waning immunity and subpar vaccine efficacy (VE).
Why this matters
- Ensure that pediatric patients are current on DTaP vaccines.
- Administer Tdap (tetanus-diphtheria-pertussis) vaccine in adolescents ages 11-12 years or catch up at next clinical visit in ages 13-18 years.
- 469,982 children, 2,138,835 person-years:
- 738 PCR-confirmed pertussis cases, 13% (n=99), 5% (36), 70% (515), 12% (88) unvaccinated, undervaccinated, fully vaccinated, and fully vaccinated plus 1 dose children, respectively.
- Pertussis risk 13 times higher in unvaccinated (adjusted HR [aHR], 13.53; 95% CI, 10.64-17.21), 1.9 times higher in undervaccinated (aHR, 1.86; 95% CI, 1.32-2.63) vs fully vaccinated children.
- Children (19 to
- Children >84 to 132 months, risk was >4 times higher ≥6 years post-last DTaP dose vs
- Retrospective cohort study to determine pertussis risk by DTaP vaccination status, time since last DTaP in children born between 1999 and 2016.
- Funding: Kaiser Permanente Northern California, NIH.
- Reduced precision estimates.
- Missed cases.
- Misclassification bias.