Safety Study of a Capsule-Conjugate Vaccine to Prevent Campylobacter-Caused Diarrhea

This is an open-label, dose-escalating study in which a total of 48 healthy volunteers will receive 2 vaccinations (one on Day 0 and one on Day 28 ± 2 days).

There are 3 cohorts (dose levels) with 2 groups of 8 volunteers in each cohort. A cohort will be administered one of 3 intramuscular (IM) doses at 2 μg, 5 μg, or 10 μg of Capsule-Conjugate Campylobacter Vaccine (CJCV1) with or without Alhydrogel®, aluminum hydroxide adjuvant (alum) at 125 μg.

An interval no less than 1 week will separate the last dose of a volunteer group from the first dose of the next volunteer group (receiving different CJCV1 doses). Blood specimens will be collected at intervals to examine systemic and mucosal antigen-specific immune responses. Vaccine safety will be actively monitored during vaccination and for 28 days (± 2 days) following the second vaccination and complete the study with a telephone follow-up approximately 6 months (± 1 month) after the first vaccination. The total duration of participation in this study is up to 270 days (including screening).

Inclusion criteria

• Healthy adult, male or female, age 18 to 50 years (inclusive) at the time of enrollment.
• Completion and review of comprehension test (achieved 70% accuracy).
• Signed informed consent document.
• Available for the required follow-up period and scheduled clinic visits and telephone follow-up.
• Women: Negative pregnancy test with understanding (through informed consent) to not become pregnant during the study or within three months after the last vaccine dose (Day 28). Sexually active females, unless surgically sterile or at least one year postmenopausal, must have used an effective method of avoiding pregnancy (including oral or implanted contraceptives, intrauterine device (IUD), female condom, diaphragm with spermicide, cervical cap, abstinence, use of a condom by the sexual partner, or sterile sexual partner) prior to dosing of study vaccine. Female subjects unable to bear children must have a note from a primary care provider or obstetrics and gynaecology (OB/GYN) as proof of documentation (eg, tubal ligation or hysterectomy). If a volunteer becomes pregnant during the study, the PI will notify the study monitor, the sponsor, and the local institutional review board (IRB). The volunteer will be asked to provide serial follow-ups, including copies of clinic visits on the status of her pregnancy as well as health information on her infant following delivery.

Exclusion criteria

Health

• Health problems affecting study participation from medical history (specifically to include chronic medical conditions such as diabetes mellitus and hypertension or any other condition requiring daily therapy that would place the volunteer at increased risk of adverse events (AEs). Study clinicians, in consultation with the PI, will use clinical judgment on a case-by-case basis to assess safety risks under this criterion. The PI will consult with the research monitor as appropriate.
• Clinically significant abnormalities on physical examination
• Use of immunosuppressive drugs, such as corticosteroids and chemotherapy, during the course of the study or immunosuppressive illness, including IgA deficiency (defined by serum IgA below level of detection)
• Women who are pregnant or planning to become pregnant during the study period plus 3 months beyond the last vaccine dose and currently nursing women
• Participation in research involving another investigational product 30 days before the planned date of first vaccination until the last study safety visit.
• Positive blood test for HIV-1 (the human immunodeficiency virus and cause of AIDS)
• Positive blood test for hepatitis B surface antigen (HBsAG; the virus causing hepatitis B)
• Positive blood test for anti-HCV antibody (the virus causing hepatitis C)
• Clinically significant abnormalities on basic laboratory screening
• Presence of significant unexplained laboratory abnormalities that in the opinion of the PI may potentially confound the analysis of the study results Research Specific
• Regular use (weekly or more often) of anti-diarrheal, anti-constipation, or antacid therapy
• Abnormal bowel habits as defined by fewer than 3 stools per week or more than 3 loose/liquid stools per day
• Personal or family history of inflammatory arthritis
• Personal history of irritable bowel syndrome
• Positive blood test for HLA-B27
• History of allergy to any vaccine
• History of allergy to alum
• History of Guillain-Barré Syndrome or other neuroimmunological disorders Prior Exposure to Campylobacter
• History of travelers' diarrhea or residence (> 2 months) in the past 3 years in a country with potentially higher Campylobacter rates to include Africa, South America, Central America, and Asia (except Japan).
• Occupation involving handling of Campylobacter bacteria or vaccine products currently or in the past 3 years.
• History of microbiologically confirmed Campylobacter infection.
• Received previous experimental Campylobacter vaccine or live Campylobacter challenge.