Table 4.

Current Shigella vaccine landscape

Type	Preclinical	Phase 1, route, dose,	Ref
Live CVD seriesa	+	oral, 109–1010	118,140,142
Live WRAIR seriesb	+	ongoing	118,134,138,140,142
Live S. typhi Ty21a with Shigella LPS genes	+		130
Formalin killed cells, trivalent	+	oral, 1010–1011	117,125
Invaplexd	+	Intranasal	14,119,125-126
LPS conjugates	+	parenteral	121,125,142
Synthetic oligo-saccharides	+		133,142
Bioglycoconjugatesf	+	parenteral	132
Purified Ipa proteins	+		139
OMg vesicles	+		137

^abased on guaBA mutations, multiple serotypes, limited intracellualr replication.

^bbased on virG(icsA) mutations, multiple serotypes, inability to spread intercellularly.

^ctrivalent product with S. sonnei, S. flexneri 2a and 3a.

^dcombination of serotype-specific LPS and conserved antigens IpaB and IpaC proteins, LPS from different serotypes can be substituted.

^eLPS conjugates with CRM, a non-toxic recombinant variant of diptheria toxin with a single amino acid substitution.

^fShigella O-antigen expressed in an E. coli with Campylobacter glycosylation secretion machinery.

^gOM, outer membrane.