A Phase 4, Randomised Vaccination Study in Healthy Adults to Investigate the Effects of Acellular Pertussis Vaccine on Colonisation With Bordetella Pertussis Using Controlled Human Infection

The goal of this clinical trial is to investigate the effect of booster vaccination with acellular pertussis vaccine on colonization with Bordetella pertussis using a controlled human infection model in healthy volunteers. The main questions it aims to answer are: * Whether booster vaccination with Tdap-IPV reduces Bp colonisation after intranasal challenge with the standard Bp inoculum dose compared to the Td-IPV control group * Compare Bp colonisatation in participants vaccinated with Tdap-IPV after intranasal challenge with the standard and a 'high' Bp inoculum dose Research will compare Tdap-IPV vaccination - standard inoculum dose with Td-IPV vaccination - standard inoculum dose, and Tdap-IPV vaccination - standard inoculum dose with Tdap-IPV vaccination - high inoculum dose to see how Tdap-IPV vaccination and the high inoculum dose have an effect on colonisation rate. Participants will be vaccinated with Tdap-IPV or Td-IPV and 2-4 months later challenged with the standard or 'high' inoculum. After challenge there is a follow up visit for 28 days in which they fill in a daily symptom diary and have 6 visits to the hospital.

NCT Number	NCT06903221
Lead Sponsor	Dimitri Diavatopoulos
Conditions	Pertussis Infection, Pertussis Vaccines
Enrollment	99 participants
Start Date	2024-10-16
Primary Completion	2026-10 (estimated)
Study Completion	2027-04 (estimated)
Updated on ClinicalTrials.gov	2026-05-07