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Severe Pertussis Infections in All Age Groups

Clin Infect Dis; ePub 2018 Oct 15; Mbayei, et al

Infants aged <2 months are at the greatest risk for pertussis-related hospitalization; however, severe pertussis infections occur in persons of all ages and pertussis vaccination remains the most important tool for infection prevention. This according to a recent study that characterized pertussis infections in US hospitalized patients of all ages. Cases of pertussis with cough onset from January 1, 2011, through December 21, 2015 from 7 US Emerging Infections Program Network states were reviewed. Among the findings:

  • Among 15,492 cases of reported pertussis, 515 (3.2%) were hospitalized.
  • Infants aged <2 months accounted for 1.6% of all pertussis cases but 29.3% of hospitalizations.
  • Infants aged 2-11 months and adults aged ≥65 years also had high rates of hospitalization.
  • Infants aged <2 months whose mothers received Tdap during the third trimester and children aged 2 months to 11 years who were up-to-date on pertussis-containing vaccines had a 43-66% reduced risk of hospitalization.

Mbayei SA, Faulkner A, Miner C, et al. Severe pertussis infections in the United States, 2011-2015. [Published online ahead of print October 15, 2018]. Clin Infect Dis. doi:10.1093/cid/ciy889.


This study reinforces that pertussis can affect all ages. There used to be thoughts that natural infection gave lifelong immunity, but it is more likely to be 15 years. The immunity from an acellular vaccine gives up to 5‒6 years of protection with less years of protection with the Tdap. This is why the third trimester immunization program shows that these newborns under 2 months of age make up a tiny fraction of the US population but almost a third of hospitalizations. — John Russell, MD