Mark Slifka (ONPRC)

West Nile virus (WNV) is a mosquito-borne flavivirus that has become endemic in the United States. From 1999–2012, there have been 37,088 reported cases of WNV and 1,549 deaths, resulting in a 4.2% case-fatality rate. Despite development of effective WNV vaccines for horses, there is no licensed vaccine to prevent human WNV infection. Several vaccines have been tested in preclinical studies, and to date there have been eight clinical trials, with promising results in terms of safety and induction of antiviral immunity. Although mass vaccination is unlikely to be cost effective, implementation of a targeted vaccine program may be feasible if a safe and effective vaccine can be brought to market.

NHP provide an important resource for WNV vaccine development due to the similarities of NHP and human immune response to this viral pathogen. This attribute allows direct comparisons of vaccine antigens, delivery systems and adjuvants that may predict the potency and specificity of responses and potential correlates of protection prior to the clinical development stage. Although NHP do not typically present with clinical signs of disease after experimental WNV infection, recent studies (B.E. Verstrepen et al. PLoS Neg Trop Dis 2014;8:e2797) have found that rhesus macaques and common marmosets are susceptible to infection with a virulent European strain of WNV (WNV-Ita09) and present with higher levels of viremia/RNAemia than that observed in previous studies that used the WNV-NY99 strain of virus. Both models of WNV infection are deserving of further study, especially in terms of testing the efficacy of future WNV vaccines and therapeutics.

Recent NPRC Publications

There are currently 14 publications available for West Nile virus.


Aguilar-Valenzuela R, Netland J, Seo YJ, Bevan MJ, Grakoui A, Suthar MS
Dynamics of Tissue-Specific CD8+ T Cell Responses during West Nile Virus Infection.
Journal of virology 2018 05; 92(10): .


Poore EA, Slifka DK, Raué HP, Thomas A, Hammarlund E, Quintel BK, Torrey LL, Slifka AM, Richner JM, Dubois ME, Johnson LP, Diamond MS, Slifka MK, Amanna IJ.
Pre-clinical development of a hydrogen peroxide-inactivated West Nile virus vaccine.
Vaccine 2017 Jan; 35(2): 283-292.


Gokhale NS, McIntyre ABR, McFadden MJ, Roder AE, Kennedy EM, Gandara JA, Hopcraft SE, Quicke KM, Vazquez C, Willer J, Ilkayeva OR, Law BA, Holley CL, Garcia-Blanco MA, Evans MJ, Suthar MS, Bradrick SS, Mason CE, Horner SM.
N6-Methyladenosine in Flaviviridae Viral RNA Genomes Regulates Infection.
Cell Host Microbe 2016 Nov; 20(5): 654-665.


Fish I, Boissinot S.
Contrasted patterns of variation and evolutionary convergence at the antiviral OAS1 gene in old world primates.
Immunogenetics 2015 Sep; 67(9): 487-99.

Lubick KJ, Robertson SJ, McNally KL, Freedman BA, Rasmussen AL, Taylor RT, Walts AD, Tsuruda S, Sakai M, Ishizuka M, Boer EF, Foster EC, Chiramel AI, Addison CB, Green R, Kastner DL, Katze MG, Holland SM, Forlino A, Freeman AF, Boehm M, Yoshii K, Best SM.
Flavivirus Antagonism of Type I Interferon Signaling Reveals Prolidase as a Regulator of IFNAR1 Surface Expression.
Cell Host Microbe 2015 Jul; 18(1): 61-74.


Recent News Articles and Reference Materials

December 18, 2015
Findings show promising evidence for creating broad-spectrum antiviral

July 8, 2015
Vaccine against West Nile virus to be tested in people, health officials say

July 6, 2015
NIH-Funded Vaccine for West Nile Virus Enters Human Clinical Trials

May 7, 2015
First-of-its-kind West Nile virus vaccine now in Phase I clinical trials

May 7, 2015
NIH-sponsored Phase 1 clinical trial evaluates novel investigational West Nile virus vaccine

April 10, 2015
California drought linked to West Nile virus outbreak

September 22, 2014
In California, Less Water Means More West Nile Virus

CDC Resource Page: West Nile virus