New Bird Flu Vaccine Nears Human Tests
DNA-Based Vaccine Could Be Ready Fast if Flu Pandemic Hits
Will It Work? continued...
But Treanor warns that lots of vaccine approaches that look promising in
mice never turn out to work in men and women. And he notes that experimental
adenovirus vaccines have yet to live up to their potential.
"While adenoviruses have been evaluated as potential vaccine vectors for
many years, there is no human vaccine that uses adenovirus for a vector,"
Treanor says. "There is no evidence that an adenoviral vaccine can protect
humans against any disease except adenovirus."
Gambotto says this situation soon may change.
"I think this adenovirus technology is like the electric car,"
Gambotto says. "We all know that sooner or later we will drive an electric
car. The technology just isn't quite there yet. But soon we will all be driving
Bird Flu Vaccines -- What's Next?
Gambotto says if the adenovirus vaccine works, it could be geared up to full
production very soon after a flu pandemic breaks out.
Treanor warns, however, that the time savings offered by new technologies
won't resolve all the problems with making a pandemic flu vaccine.
"This is not going to have as big an effect on the time to make a
vaccine as you might think," he says. "It is generating the
[ingredients needed to produce vaccine], it is the processing time, it is the
putting-things-in-vials time, and all the other steps involved in making a
vaccine," he says. "Growing a virus is one thing, but not the only
thing. A process like this where you clone the gene into something would be
faster. You shave time off the growth of the product, but there are other
components that would still pose a time barrier."
Treanor hopes that the Gambotto team succeeds. If they don't, it's not the
only chance for improved bird flu vaccines.
The next big breakthrough, Treanor predicts, will be finding a way to
stretch out vaccine supplies by making small doses more effective. This can be
done by giving the vaccine along with a substance called an adjuvant. Treanor
says a new adjuvant, called MF59, looks very promising.
And Treanor notes that researchers at the National Institutes of Health are
exploring a live-virus bird flu vaccine.
There's already a live-virus vaccine for seasonal flu -- FluMist.
"A development program at NIH is trying to make an H5 version of
FluMist," Treanor says. "When we see how effective that is, that could
be a big thing."