The National Institutes of Health have announced that an experimental vaccine to protect against West Nile Virus is to enter human trial.

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The developers say because the vaccine uses inactivated virus it should be suitable for a wide range of people.

The trial will test the safety of the vaccine – called HydroVax-001 – and its ability to produce an immune response in human subjects.

In lab trials, the vaccine protected mice against lethal doses of West Nile Virus.

The tests showed the vaccinated animals’ immune systems responded with the appropriate antibodies and CD8+ T cells, which bind to and kill infected cells.

The randomized, placebo-controlled, double-blind phase 1 clinical trial will be conducted by researchers at Duke University School of Medicine, Durham, NC, and is expecting to enrol 50 healthy volunteers – men and women aged between 18 and 50 years – by December 2015.

The participants will be randomly assigned to one of the three groups. One group of 20 volunteers will receive a low dose of the vaccine (1 mcg), another 20 volunteers will receive a higher dose (4 mcg) and a group of 10 volunteers will receive a placebo.

All participants will receive their doses via intramuscular injection on day 1 and day 29 of the trial and will be followed for 14 months.

The vaccine was developed by scientists at Oregon Health & Science University (OHSU) in Portland. The vaccine uses inactivated virus and cannot cause West Nile Virus infection.

Led by OHSU senior scientist Dr. Mark Slifka, the team created the vaccine using a new hydrogen peroxide process that inactivates the virus while preserving the ability of key surface virus structures to trigger the appropriate immune response.

The researchers say that because the vaccine uses inactivated virus it should be suitable for a wide range of people, including vulnerable groups like the elderly and people with weak immune systems.

West Nile Virus is spread by mosquitoes in many parts of the world. It first emerged in the Western Hemisphere in 1999 in the New York City area and has since spread across the US.

Most people infected with the virus feel no symptoms, while around 1 in 5 feel like they have the flu and experience mild symptoms such as headache, muscle ache and fever, possibly with nausea and vomiting.

However, around 1 in 150 people who become infected with West Nile Virus experience serious problems, including encephalitis (inflammation of the brain) or meningitis (inflammation of the lining around the brain and spinal cord). In these cases the infection can be fatal.

In the US, West Nile Virus infection is typically a seasonal epidemic that begins in late spring or early summer and continues into the fall. 2,205 cases of West Nile Virus infection and 97 related deaths were reported in 2014 in the US.

The vaccine trial is being sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. NIAID Director Dr. Anthony S. Fauci, says:

Since first appearing in the United States in 1999, West Nile Virus has emerged as an important health threat in this country. NIAID is committed to research efforts to advance a preventive vaccine that could protect people against West Nile Virus infection.”

You can see detailed information about the trial on the website by looking up the trial reference number NCT02337868.

Earlier this year, Medical News Today learned that public health experts are warning that climate change could accelerate the arrival in the UK of West Nile Virus and other diseases that are transmitted by mosquitoes and other insects.