Joining a worldwide effort to safeguard humanity from the growing risk of avian influenza, University of Wisconsin researchers developed a more efficient method of producing vaccines to combat the disease.
In collaboration with researchers from the University of Tokyo, UW virologists Yoshihiro Kawaoka and Gabriele Neumann have found a technique to bypass many of the lengthy processes that often complicate the vaccine's production.
Kawaoka and Neumann formally announced their findings in the online edition of the Proceedings of the National Academies of Science.
By employing "reversed genetics" — a process devised by Kawaoka's group in 1999 — scientists can generate disarmed virus particles faster and easier. In traditional reverse genetic methods, vaccines can be produced by seeding disarmed, lab-made viruses into chicken eggs, which provide host cells for virus reproduction.
Following the new method, scientists are able to package many of the circular bits of viral DNA, known as plasmids, into three combined units and seed them into monkey kidney cells.
"Compared to other types of cells, which are not approved for vaccine production, it is not always easy to introduce plasmids into the monkey kidney cells, which are approved for such use," Kawaoka, a pathological sciences professor in the School of Veterinary Medicine, said in a released statement.
Because of the smaller amount of plasmids involved in the delicate process, more disarmed viruses can be created in a smaller amount of time.
"Application of the new system may be especially advantageous in situations of outbreaks of highly pathogenic avian influenza viruses," Kawaoka said.
Because viruses often mutate, it can be difficult for scientists to continuously produce new seed strains to keep up. Under Kawaoka's process, seed-strain manufacturers can more easily produce new viruses.
Associate professor of family medicine Jonathon Temte said new methods are "always desired" to speed up an otherwise lengthy vaccine-production and approval process, but it may be pretentious to say the new findings offer a panacea for a potential bird flu pandemic.
"I think the big issue with avian influenza right now [is] whether or not it becomes a pandemic influenza strain that affects millions of humans," he said. "One has to distinguish between the current virus out there and one that is transmittable from human to human."
Temte added findings so far have suggested humans cannot contract the virus unless an individual is exposed to a considerable amount of the virus from an infected bird.
"It's a relatively safe virus unless you're a chicken or a duck or other fowl species," he said. "So it's a bad thing if you're a bird, it's bad if you get a whole lot of it if you're a human, but it's not being transferred from one person to the next, so that's a good thing."
But Temte said the "bad thing" remains that there are immeasurable numbers of different virus strains currently affecting the world's bird population and, until a certain strain is identified as being transmittable from human to human, scientists can only theorize which ones could produce a pandemic.
"Right now, we don't have one that's circulating in humans," he said. "We could come up with one that's somewhat close, but that might not be good enough."
