BBC NEWS Americas Africa Europe Middle East South Asia Asia Pacific Arabic Spanish Russian Chinese Welsh

 You are in:  Health
Front Page 
UK Politics 
Background Briefings 
Medical notes 
Talking Point 
In Depth 

Commonwealth Games 2002

BBC Sport

BBC Weather

Tuesday, 5 March, 2002, 00:31 GMT
Vaccine developed for West Nile virus
West Nile virus is spread by mosquitoes
Scientists have developed a vaccine for the deadly West Nile virus (WNV).

It is a hybrid vaccine made up of a combination of weakened forms of the viruses that cause West Nile virus and dengue fever.

WNV occurs in many parts of the world. In 1999, seven died and dozens were infected by the virus following an outbreak in New York - the first time it had been found in North America.

WNV usually causes only mild symptoms, but it can spread to the central nervous system and cause a potentially deadly brain inflammation called encephalitis.

We must remain vigilant and act quickly if we are to keep ahead of emerging and re-emerging infectious agents such as West Nile virus

Dr Anthony Fauci
The vaccine is formed by removing key genes from dengue virus and replacing them with WNV genes.

Researchers will begin testing the vaccine in monkeys next month and hope to begin human trials in late 2002.

Both WNV and dengue virus are flaviviruses, a group of microbes, spread by ticks and mosquitoes that also include the viruses that cause yellow fever, St. Louis encephalitis and other illnesses.

The new vaccine has been developed by a team from the US National Institute of Allergy and Infectious Diseases (NIAID) and the Walter Reed Army Institute of Research.

The hybrid vaccine consists mostly of dengue virus, which does not target the central nervous system. Therefore, it does not infect the brain.

In laboratory tests, the researchers found that the WNV genes stimulated a powerful immune response in mice who were given just one shot of the vaccine.

One of the dengue viruses used by the researchers to construct the genetic backbone of the hybrid virus had already been proven safe in people.

The researchers therefore hope they will be able to quickly move the new vaccine from tests in monkeys to clinical trials in humans.

Researcher Dr Anthony Fauci said: "We must remain vigilant and act quickly if we are to keep ahead of emerging and re-emerging infectious agents such as West Nile virus.

"Disease-causing microbes will continue to adapt and continue to thrive, so we cannot let down our guard."

The research is published in the Proceedings of the National Academy of Sciences.

See also:

04 Aug 00 | Health
Virus panic grips US east coast
01 Nov 00 | Latest News
Sparrows blamed for killer disease
Internet links:

The BBC is not responsible for the content of external internet sites

Links to more Health stories are at the foot of the page.

E-mail this story to a friend

Links to more Health stories