Table 2.

WNV vaccine concepts that have reached the clinical stage.

Vaccine name (sponsor)	Vaccine type	Antigen	Phase (year)	Target group	Study design	Summarized results or Trial ID
Chimerivax-WN02 (Sanofi Pasteur)	Live attenuated chimeric	Prm and E of WNV NY99 into YEF 7D virus	Phase II	18–40 y (n = 95)	1-dose (dose-ranging)	PRNT seroconversion: >96% all (dose and age) groups
			2005–9 33	41–64 yrs (n = 33)	4.103, 4.104 and 4.105 pfu	PRNT seroconversion: 92–95% all (dose) groups
			2008/9 34	≥ 65 yrs (n = 31)	4.105 pfu
				≥50 years (n = 359)	4.105 pfu
					1-dose (dose-ranging)
					4.103, 4.104 and 4.105 pfu
VRC-WNVDNA020-00-VP 35	Plasmid DNA	Prm, E of WNV NY99 with CMV/R promotor	Phase I 2006 35	healthy adults (n = 30)	3-dose regimen	Vaccine-induced antibody (ELISA) response in both age groups in 93%
(replaces VRC-WNVDNA017-00 VP 36) (NIAID)				split in: 18–50 y (n = 15)		Vaccine-induced neutralizing antibody response in both age groups in 97%
				51–65 y (n = 15)		24–45% showed CD4+ or CD8+ T cell responses to E and Prm peptide pools
WN/DEN4-3′Δ30 (NIAID)	Live attenuated chimeric	Prm, E of WNV NY99 into dengue type 4 virus	Phase I 2004 37	18–50 y	1 dose (103, 104 or 105 pfu)	Seroconversion was observed in 74% (103 PFU), 75% (104 pfu), and 55% (105 PFU)
			2007 37	18–50 y	2-dose regimen (104 or 105 pfu)	A 2nd (105 pfu) dose 6 months after first dose increased the seroconversion rate to 89%.
			2014 38	50–65 y (n = 28)	2-dose regimen (104 pfu)	Seroconversion rate 95%
WN-80E (other name HBV-002) (Hawaii Biotech)	Rec. E subunit to aluminium hydroxide	E	Phase I 2008–9 39			Low level neutralizing antibodies
HydroVax-001 (NIAID)	Inactive whole WNV virion		Phase I 2015			NCT02337868

CMV, cytomegalovirus; E, envelope protein; pfu, plaque forming units; Prm, premembrane protein; PRNT; plaque reduction neutralization titers; n, numbers of participants that received the WNV vaccine; NIAID, National Institute of Allergy and Infectious Diseases; NY99, New York 1999 WNV strain; YEF, yellow Fever.