Pertussis Challenge Study in Adults Vaccinated With BPZE1

This Phase 2b challenge study will investigate colonisation rates, immunologic response, and the safety of BPZE1 vaccination to potentially protect against colonising, virulent wild-type B. pertussis infection in healthy adults using a virulent challenge model. Consenting, eligible participants will receive a single dose of BPZE1 or placebo. 2-4 months later they will be challenged with B. pertussis and admitted to a challenge unit. Participants will remain in the challenge unit for a total of 17 days and 16 nights during which time they will be monitored closely. If a participant develops symptoms of pertussis (per investigator discretion), antibiotic (azithromycin) will be started and the participant will remain in the unit for 3 additional days of observation before discharge. If symptoms of pertussis do not develop, then participants will receive antibiotic (azithromycin) from Days 14-16 of the challenge unit stay. Participants will undergo safety follow-up for at least 6 months post-vaccination and at least 3 months post-challenge, for a total follow-up of 6-7 months.