Controlled Human Infection Model: Bordetella pertussis
Full title: Double-blind, placebo-controlled, phase 1/2, dose-escalation clinical trial to establish a Controlled Human Infection Model by determining the optimal and safe J820 Bordetella pertussis dose administered intranasally to healthy adults 18–50 years of age that induces mild-to-moderate symptomatic infection, specifically early catarrhal pertussis infection with cough, with detection of B. pertussis in nasal samples.
What is the purpose of this study?
This study is a Controlled Human Infection Model (CHIM) to find out how much of the bacteria that causes whooping cough is needed to make healthy adults only slightly sick.
At the same time, we will be studying both what the bacteria is doing inside the body and the immune system’s response to it.
Why do researchers want to find that out?
There are two main reasons for these kinds of studies:
-
In this study, we are using a strain of B. pertussis similar to what is currently being spread in North America.
This strain has had a change in its genetic code that means it no longer makes a protein called pertactin (PRN). PRN is a protein that helps the bacteria stick to human cells and avoid being detected by the immune system.
Many pertussis vaccines use PRN as an antigen (the thing that triggers our immune system). These vaccines teach our immune system “If PRN is detected, it’s time to get to work”.
However, some strains of pertussis no longer make PRN, so our immune systems can’t find it. This means that whooping cough can continue to spread, even in vaccinated people. These strains without PRN are now the most common in North America.
This research could help us understand how the lack of PRN affects infections and improve future vaccines to protect against new strains of whooping cough.
-
In vaccine challenge trials, participants are given a new vaccine a few weeks before agreeing to be infected with an illness such as whooping cough or the flu.
Standard clinical trials that test new vaccines usually need thousands of volunteers and take a lot of time to complete. This is because they need to wait for enough participants to come in contact with a virus or bacteria in their daily lives to say the vaccine prevented illness most of the time.
Because of what we learned in CHIM studies, vaccine challenge trials can give participants just enough virus or bacteria to be able to say they are infected but avoid the worst of feeling sick.
This allows researchers to test new vaccines a lot faster and with fewer volunteers because they don’t have to wait on the chance someone might get sick.
You may be able to take part if you are:
18-50 years old.
able and willing to stay in a private room at the IWK for up to 24 days.
in generally good health and pass the medical pre-screening.
What will I have to do?
Volunteers selected for the study will spend up to 24 days in a private room inside the Challenge Unit at the IWK.
After having a day to settle in, you will be carefully exposed to a strain of Bordetella pertussis to develop a very mild case of whooping cough.
Samples like blood, urine, and nasal/throat swabs will occur a few times a day. We will give you a daily schedule so you know when these samples will take place. What you do with the time between samples is entirely up to you!
During your stay, physical and mental health support is available 24/7.
If you show symptoms or test positive for whooping cough, you will be given antibiotics as soon as they appear to clear up the infection. Most study participants only feel mild discomfort from the sample collection and the infection.
Once the infection is cleared, you can return home. You may withdraw from the study at any time. The study team will provide antibiotics for home care and will follow up after your discharge to ensure you are feeling better.
After the inpatient period, there is a follow-up period of one year with intermittent visits and phone calls.
Learn more about what it is like to take part in a challenge study by visiting our Participation page.