West Nile Virus Protein Particles Give Immunity in Mice

[Guest guest]

[sounds promising, but it will take several years (at least) for a

human vaccine to be produced. This vaccine would not be able to

cause the WNV by itself, which would be important in an immuno-

compromised population.]

West Nile Vaccine Produces Immunity in Mice

Wed Dec 29, 3:39 PM ET Health - Reuters

By Anne Harding

NEW YORK (Reuters Health) - Mice injected with a purified structural

protein from the West Nile virus (news - web sites) (WNV) develop

immunity against infection, new research shows.

The findings suggest WNV-like particles could be used as a vaccine,

Dr. T. Jake Liang of the National Institutes of Health (news - web

sites) in Bethesda, land, and colleagues report in the Journal of

Infectious Disease.

Because the particles are produced using genetic engineering

techniques, the researchers note, they avoid the risks of some other

WNV vaccine candidates.

" There's really no infectious virus in there; you can really control

very easily in terms of quality and purity, " Liang told Reuters

Health. " We can certainly scale up and make large quantities of it. "

Liang and his team produced the WNV-like particles by growing a

harmless baculovirus that was engineered to express two WNV proteins -

- prME or CprME -- in insect cells.

Mice were immunized with either protein four times at 3-week

intervals, and then challenged with actual West Nile virus two months

later.

The researchers saw the strongest immune response in animals given

prME, and none of them died or became sick. In contrast, two-thirds

of the group given CprME died.

The next steps in the research will be to test the vaccine in

monkeys, and with good results trials in humans can follow, Liang

said.

SOURCE: Journal of Infectious Disease, December 15, 2004.