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


O'Neal JT, Upadhyay AA, Wolabaugh A, Patel NB, Bosinger SE, Suthar MS
West Nile Virus-Inclusive Single-Cell RNA Sequencing Reveals Heterogeneity in theType I Interferon Response within Single Cells.
J Virol. 2019 Mar 5;93(6). pii: JVI.01778-18. doi: 10.1128/JVI.01778-18. Print2019 Mar 15. 2019.

Quintel BK, Thomas A, Poer DeRaad DE, Slifka MK, Amanna IJ
Advanced oxidation technology for the development of a next-generationinactivated West Nile virus vaccine.
Vaccine. 2019 Jul 9;37(30):4214-4221. doi: 10.1016/j.vaccine.2018.12.020. Epub2018 Dec 31. 2019.

Roe K, Giordano D, Young LB, Draves KE, Holder U, Suthar MS, Gale M Jr, Clark EA
Dendritic cell-associated MAVS is required to control West Nile virus replicationand ensuing humoral immune responses.
PLoS One. 2019 Jun 26;14(6):e0218928. doi: 10.1371/journal.pone.0218928.eCollection 2019. 2019.

Tisoncik-Go J, Gale M Jr
Microglia in Memory Decline from Zika Virus and West Nile Virus Infection.
Trends Neurosci. 2019 Sep 5. pii: S0166-2236(19)30159-6. doi:10.1016/j.tins.2019.08.009. 2019.

Woods CW, Sanchez AM, Swamy GK, McClain MT, Harrington L, Freeman D, Poore EA, Slifka DK, Poer DeRaad DE, Amanna IJ, Slifka MK, Cai S, Shahamatdar V, Wierzbicki MR, Amegashie C, Walter EB
An observer blinded, randomized, placebo-controlled, phase I dose escalationtrial to evaluate the safety and immunogenicity of an inactivated West Nile virus Vaccine, HydroVax-001, in healthy adults.
Vaccine. 2019 Jul 9;37(30):4222-4230. doi: 10.1016/j.vaccine.2018.12.026. Epub2019 Jan 18. 2019.


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