Healthy
Conditions
Keywords
Vivotif, Typherix, Salmonella Typhi, non-typhoid Salmonella, Salmonella Paratyphi, enzyme-linked immunospot assay, Plasmablast
Brief summary
In a recent controlled study, the investigators explored cross-reactive immune responses against different Salmonella spp. in healthy volunteers immunized with either the oral (Vivotif® ) or parenteral (Typherix®) typhoid vaccines (ISRCTN68125331). In the present study immune responses will be studied in a group receiving both of these vaccines and in the previously immunized volunteers after booster immunization (same groups receive same vaccines 2-4 years after primary immunization).
Detailed description
Many Salmonella spp causing gastroenteritis share O antigen serotypes with Salmonella enteritidis subsp. enterica serovar Typhi (S.typhi) and could therefore be in 'reach' of the protective efficacy of the oral live typhoid fever vaccine Vivotif®. Some of these Salmonellae are common causes of diarrhoea in travellers (0-30% of travellers diarrhea depending on the area). In a recent controlled study, the investigators showed that a cross-reactive immune response is elicited against different Salmonella spp. in healthy volunteers immunized with either the oral (Vivotif® ) or parenteral (Typherix®) typhoid vaccines (ISRCTN68125331). In the present study immune responses will be studied in a group receiving both of these vaccines and in previously immunized volunteers after booster immunization (same groups receive same vaccines 2-4 years after primary immunization; groups: Vivotif / Typherix / Vivotif + Typherix). The results are compared to those obtained after primary immunization.
Sponsors
Helsinki University Central Hospital
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 64 Years
Healthy volunteers
Yes
Inclusion criteria
1. Male or female subjects aged ≥18 to ≤65 years 2. General good health as established by medical history and physical examination 3. Written informed consent 4. Females of childbearing potential must agree to use an efficacious hormonal or barrier method of birth control during the study. Abstinence is acceptable. 5. Available for all visits scheduled in this study.
Exclusion criteria
1. Primary groups: Vaccination against typhoid fever within 5 years before dosing. 2. History of clinical typhoid fever, clinical paratyphoid A or B fever. 3. Immunization with any other vaccine (oral or parenteral) within 4 weeks prior to study start or planned vaccination during the study 4. Current intake of antibiotics or end of antibiotic therapy \<8 days before first IMP administration 5. Chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of investigational vaccine; oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent are excluded; inhaled or topical steroids are allowed 6. Acute or chronic clinically significant gastrointestinal disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of circulating plasmablasts specific to various Salmonella strains | 7 days | To study whether cross-reactive immune response is similar * if the two vaccines are given simultaneously * after booster immunization than after primary immunization |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Level of serum antibodies specific to various Salmonella strains | 28 days | To study whether cross-reactive serum immune response is similar * if the two vaccines are given simultaneously * after booster immunization than after primary immunization |
Other
| Measure | Time frame | Description |
|---|---|---|
| Safety | 28 days | Record adverse effects of the vaccines used |
Countries
Finland
Contacts
Primary ContactAnu Kantele, Assoc. prof.
Backup ContactSari H Pakkanen, MSc
Outcome results
None listed