A population-based Study of Recurrent Symptomatic Bordetella pertussis Infections in Children in California, 2010–2015

Natural infection with Bordetella pertussis is thought to result in 4–20 years of immunity against subsequent symptomatic pertussis infection. However, these estimates are based on studies in unvaccinated or whole-cell vaccinated children. We conducted a population-based study of pertussis infection and reinfection during a 5-year period in California in an exclusively acellular-pertussis vaccinated cohort.

California surveillance data were reviewed to identify all children with two reported incidents of pertussis with symptom onset from January 1, 2010 through December 31, 2015. Case investigation reports were reviewed and children with at least two episodes of symptomatic pertussis infection that met the case definition were included.

Of 26,259 pertussis cases reported in children <18 years, 27 children met the inclusion criteria. Recurrent cases occurred among children of all ages, and the median age for the first and second pertussis episodes were 3.5 years (range, 1.3 months-14 years) and 6.5 years (range, 5.2 months–16.3 years) respectively. The median duration of time between initial infection and reinfection was 1.3 years (range, 2.9 months–4.4 years). Twenty-one children (78%) had received ≥3 doses of DTaP vaccine at the time of their first pertussis infection, 1 (4%) had received 1 dose, and 5 (19%) were unvaccinated.

Recurrent cases of pertussis infection are very rare. Contrary to previous reports that natural infection with B. pertussis results in 4–20 years of sterilizing immunity, we demonstrate that symptomatic reinfection with pertussis can occur as soon as 89 days following the first infection. More research is needed to understand the immune response to B. pertussis infection in children vaccinated with acellular-pertussis vaccines.

All authors: No reported disclosures.