Enterotoxigenic E. coli (ETEC) diarrhoea Infections and Infestations Enterotoxigenic Escherichia coli infection
Conditions
Interventions
Healthy adult volunteers will be immunised with two consecutive doses of two different ETEC vaccines (Vaccine A and Vaccine B) with 12-16 days interval. Vaccine A consists of ETEC bacteria that over-e
each dose containing 4 times higher numbers of bacteria and 4 times more LTB/CTB protein compared to the second arm
Sponsors
Gothenburg University Vaccine Research Institute (GUVAX) (Sweden)
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Males or females aged 18-55 years 2. Healthy constitution as established by medical history, medical examination and clinical chemistry and haematology testing 3. Give written informed consent to participate 4. Willing and able to communicate with the investigators and understand the requirements of the study 5. Sexually active females should unless being menopausal agree to use reliable contraception as assessed by the investigator, during 1 month prior to inclusion and one month after the last intake of study vaccine and should have a negative pregnancy test before each vaccination
Exclusion criteria
Exclusion criteria: 1. Has received the oral cholera vaccine Dukoral® in the last 5 years 2. Travelled to ETEC-endemic area within the last 2 years 3. Concomitant intake of immunomodulating drugs during the study period or less than four weeks prior to the first immunisation 4. Vaccination with some other vaccine during the study period or within two weeks prior to trial vaccination 5. Any condition which would limit the subject?s ability to complete the study in the opinion of the investigator 6. History of drug or chemical abuse in the year before the study 7. Receipt of any other investigational product in the month before study entry 8. Concomitant participation in any other clinical study 9. Donation of blood 6 weeks before study entry or at any time during the study 10. Females who are pregnant 11. Females who are nursing 12. History of gastrointestinal or systemic inflammatory or autoimmune disease 13. Any known hypersensitivity to any ingredient in the vaccines 14. Gastroenteritis within two weeks prior to vaccination 15. Antibiotic therapy within six weeks prior to the vaccination
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 1. To evaluate the safety of a new prototype ETEC vaccine (Vaccine A) and to compare the immunogenicity, i.e. intestinal or intestine-derived IgA antibody responses, against CFA/I and LTB, of the new prototype ETEC vaccine with that of a previously tested ETEC strain in combination with CTB (Vaccine B) 1.1. The safety of the vaccines will be determined by evaluation of study diaries throughout the study period, by clinical chemistry and haematology tests (at screening and 7 days after each immunisation) and by physical examination (at screening and on day 42) 1.2. Intestinal antibody responses are based on enzyme-linked immunosorbent assay (ELISA) measurements of specific antibodies in stool extracts (day 0, 7 and 21) 1.3. Intestine-derived antibody responses are based on ELISA measurements of specific antibodies secreted from cultured peripheral blood cells (using the ALS method) or on ELISPOT assay determinations of the numbers of specific antibody secreting cells (ASC) among peripheral blood mononuclear cells (day 0, 7 and 21) | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. To evaluate IgA and IgG antibody responses against CFA/I, LTB and CTB in serum as well as specific IgA in those mucosal samples that are not used as primary endpoints 1.1. Serum and intestinal antibody responses are based on enzyme-linked immunosorbent assay (ELISA) measurements of specific antibodies in sera (day 0, 7, 14, 21 and 42) and stool (day 0, 7 and 21), respectively 1.2. Intestine-derived antibody responses are based on ELISA measurements of specific antibodies secreted from cultured peripheral blood cells (using the ALS method) or on enzyme-linked immunosorbent spot (ELISPOT) assay determinations of the numbers of specific antibody secreting cells (ASC) among peripheral blood mononuclear cells | — |
Countries
Sweden
Outcome results
None listed