Double blind, randomized, controlled, dose-escalation Phase 1 clinical trial in hookworm-exposed children aged 6 to 10 years living in the area of Lambaréné, Gabon. Children will receive three doses of the assigned vaccine(s) delivered intramuscularly (deltoid) on approximately Days 0, 56, and 112 or 180.
Safety will be measured from the time of each study vaccination (Day 0) through 14 days after each study vaccination by the occurrence of solicited injection site and systemic reactogenicity events.
Unsolicited non-serious adverse events (AEs) will be collected from the time of the first study vaccination through approximately 1 month after each study vaccination. New-onset chronic medical conditions and Serious Adverse Events (SAEs) will be collected from the time of the first study vaccination through approximately 9 months after the third study vaccination (final visit). Clinical laboratory evaluations for safety will be performed on venous blood collected approximately 14 days after each vaccination.
Immunogenicity testing will include IgG antibody responses to each vaccine antigen, by a qualified indirect enzyme-linked immunosorbent assay (ELISA), on serum or plasma obtained prior to each study vaccination and at time points after each vaccination (see Appendix A); the functional activity of vaccine-induced antibodies will be assessed by in vitro enzyme neutralization assays; the induction of B cell memory will be measured by antigen-specific memory B cell responses.
Recruitment and enrollment into the study will occur on an ongoing basis, with each group being recruited and vaccinated in sequence.
60 subjects will be enrolled into 3 groups of 20. The first 20 subjects will be assembled and enrolled into Group 1:
1. Group 1 double-blind IP allocation (n=20):
* 16 subjects will receive 10 µg Na-APR-1 (M74) plus 5 µg GLA-AF delivered by IM injection in the deltoid muscle, with 10 µg Na-GST-1 administered IM in the alternate arm.
* 8 will be vaccinated according to a 0,2,4-month schedule
* 8 will be vaccinated according to a 0,2,6-month schedule
* 4 subjects will receive hepatitis B vaccine comparator:
* 2 will be vaccinated according to a 0,2,4-month schedule
* 2 will be vaccinated according to a 0,2,6-month schedule
2. Group 2 double-blind IP allocation (n=20):
* 16 subjects will receive 30 µg Na-APR-1 (M74) plus 5 µg GLA-AF delivered by IM injection in the deltoid muscle, with 30µg Na-GST-1 administered IM in the alternate arm.
* 8 will be vaccinated according to a 0,2,4-month schedule
* 8 will be vaccinated according to a 0,2,6-month schedule
* 4 subjects will receive hepatitis B vaccine comparator:
* 2 will be vaccinated according to a 0,2,4-month schedule
* 2 will be vaccinated according to a 0,2,6-month schedule
3. Group 3 double-blind IP allocation (n=20):
* 16 subjects will receive 100 µg Na-APR-1 (M74) plus 5 µg GLA-AF delivered by IM injection in the deltoid muscle, with 100 µg Na-GST-1 administered IM in the alternate arm.
* 8 will be vaccinated according to a 0,2,4-month schedule
* 8 will be vaccinated according to a 0,2,6-month schedule
* 4 subjects will receive hepatitis B vaccine comparator:
* 2 will be vaccinated according to a 0,2,4-month schedule
* 2 will be vaccinated according to a 0,2,6-month schedule
