Table 3.

Strategies for WNV subunit vaccines in preclinical assays.

Target	Strategy	Immune Response	Protection	Refolding	Ref.
E protein	Full length E and truncated (80% N-terminal)	Mice: ↑IgG titers. Antibodies recognize WNV-infected cells	Mice: 100% survival. Serum passive transfer 80% survival	No	[123]
	E antigen in a DNA prime and protein boost	Mice: ↑IgG and neutralizing Abs titers. ↑ CD8 + IFNg+ T cells	Mice: 100% survival. ↓ viremia	Yes	[124]
E ectodomain	E ectodomain plus Matrix-M (saponin) adjuvant	Mice: ↑IgG and neutralizing Ab titers	Mice: 100% survival	Yes	[119]
EDIII	EDIII fused with cholera toxin	Mice: ↑IgG, IgM and IgA titers. Complement-mediated killing of serum from immunized mice	ND	No	[125]
EDIII	EDIII genetically fused with flagelin (TLR5 agonist)	Mice: ↑IgG and neutralizing Ab titers	Mice: 100% survival	Yes	[122]
EDIII	EDIII fused with CD40 ligand	Horses: ↑IgG and neutralizing Ab titers	ND	No	[126]
EDIII	EDIII conjugated with VLP of bacteriophage AP205 plus alum	Mice: ↑IgG long-lasting response (>1 year) and neutralizing Ab titers	Mice: 100% survival	Yes	[121]
EDIII	EDIII plus CpG	Mice: ↑IgG titers. Abs recognize WNV-infected cells. ↑T-cell proliferation. ↑cytokines (splenocytes)	Mice: ↑survival of mice receiving WNV premixed with antiserum from immunized mice	No	[127]
EDIII	Comparison EDIII and soluble full-length E	Mice: partially neutralizing Abs. Different immunogens induce different potencies of neutralizing Abs	ND	No	[128]
EDIII	EDIII plus CpG and boosted with oil	Mice: ↑IgG and neutralizing Ab titers	Mice: 80% survival	Yes	[120]
EDIII	EDIII boost after E ectodomain DNA prime	Mice: ↑ IgG and neutralizing Ab titers. Moderate IFN-γ	Mice: 100% survival	Yes	[129]
EDIII	EDIII plus KFE8 peptide hydrogel	Mice: ↑ IgG and neutralizing Ab titers	Mice: 60% survival	Yes	[130]
EDIII	EDIII plus Freund’s adjuvant	Mice: ↑IgG and neutralizing Ab titers	ND	Yes	[131]

ND = not determined; ↑ = increased and ↓ = decreased.