Table 1.

Clinical Trials of Second-Generation Oral-Inactivated ETEC Vaccines^a

Trial	Vaccine	Volunteers	Publication
OEV-120, Phase 1, Sweden	Prototype vaccine (recombinant CFA/I strain + LCTBA) compared with first-generation ETEC vaccine (inactivated ETEC bacteria + CTB)	59 Swedish adults: 2 doses	Ref. [18]
OEV-121, Phase 1, Sweden	4 recombinant strains expressing CFA/I, CS3, CS5, CS6 (multivalent vaccine: 1011 bacteria + 1 mg LCTBA) ±10 or 25 µg dmLT	129 Swedish adults: 2 doses	Ref. [6]
OEV-121A, Phase 1, Sweden	Booster with multivalent ETEC vaccine	60 Swedish naive and previously immunized adults: 1 dose	Ref. [9]
OEV-122, Phase I/II, Bangladesh	Adults: ETVAX (multivalent ETEC vaccine ±10 µg dmLT) Children: fractionated doses of ETVAX ±dmLT	45 Bangladeshi adults: 2 doses 450 Bangladeshi children, 6–59 months: 2 doses	Ref. [8] Ref. [7]
OEV-123, Phase 2b, Benin	ETVAX (multivalent vaccine including 10 µg of dmLT)	729 Finnish adult travelers: 2 doses	Kantele et al [13]
OEV-124, Phase 1, Zambia	Adults: ETVAX (multivalent vaccine including 10 µg of dmLT), full dose Children: ETVAX, 1/4 or 1/8 dose	40 Zambian adults: 1 dose 229 children, 6–23 months: 2 initial doses + a booster	Sukwa et al [14]

Abbreviations: CTB, cholera toxin B subunit; dmLT, double-mutant heat-labile toxin; ETEC, enterotoxigenic Escherichia coli.

^aThe different studies were conducted during the period 2010–2021.