DGHI Professor Leading Human Clinical Trial for West Nile Virus Vaccine

Published July 28, 2015 under Research News

West Nile Virus

Microscopic image of West Nile Virus. Photo used with permission of NIAID.

The National Institute of Allergy and Infectious Diseases (NIAID) has funded a Phase 1 clinical trial of a new investigational vaccine designed to protect against West Nile Virus (WNV). Christopher Woods, professor of medicine and global health, will be leading the trial.

The experimental vaccine was discovered and developed with NIAID funding by scientists at the Oregon National Primate Research Center at Oregon Health & Science University (OHSU) in Portland. The new vaccine is being tested at Duke, one of NIAID’s Vaccine and Treatment Evaluation Units (VTEUs).

“This is an exciting step toward a strategy to prevent what is now the most common mosquito-borne infection in the United States,” said Woods.

West Nile Virus 101

Most commonly spread through the bite of infected mosquitoes, WNV infection is typically a seasonal epidemic in the United States from late spring through the fall. Last year, 2,205 cases of WNV disease and 97 related deaths were reported in the United States. 

The majority of people infected with WNV will show no symptoms. Roughly one in five people who are infected will display relatively mild symptoms, such as fever, headache, body aches, nausea, and vomiting. Only about one in 150 people infected with WNV will develop a serious neurologic illness, such as encephalitis or meningitis. 

Most people with WNV disease recover completely, but the elderly and other immunocompromised individuals are at higher risk for long-term side effects or death resulting from infection. Although an effective veterinary vaccine against WNV is available, no human vaccine has been approved for commercial use.

New Vaccine Has Been Effective in Mice

The OHSU research team created the investigational vaccine with a novel, hydrogen peroxide-based process that renders the virus inactive while still maintaining key immune-system triggering surface structures. 

The virus used to make the vaccine is inactivated and cannot cause WNV infection. Because it is inactivated, the experimental vaccine likely could be used in a diverse population, including immunologically vulnerable groups, such as the elderly.

In preclinical studies, the test vaccine was effective at protecting mice against a lethal dose of West Nile Virus. In mice, the vaccine elicited neutralizing antibody responses and CD8+ T cells, which bind to and kill infected cells.

Trial Will Test Safety and Effectiveness in Humans

The clinical trial will test the safety of the vaccine as well as its ability to produce an immune response. The trial will enroll 50 healthy men and women, ages 18 to 50 years. The volunteers will be randomly assigned to receive a low dose of the vaccine, a higher dose or a placebo. Study participants will be followed for 14 months. 

This article was adapted with permission from an NIAID news release.

This is an exciting step toward a strategy to prevent what is now the most common mosquito-borne infection in the United States.

Christopher Woods, professor of medicine and global health