The Army’s got a one-two punch to perfect vaccinations and offer scientists the ability to quickly develop inoculations that stave off new dangers. First, they’ll shoot troops up using a “gene gun,” that’s filled with DNA-based vaccines. Then they’ll follow it up with “short electrical pulses to the delivery site.”

The Pentagon’s still after a comprehensive way to inoculate troops and civilians against existing illnesses, rapidly respond to emerging threats, and even predict pathogenic mutations before they happen. To that end, the military’s already funding a handful of projects, from plant-based vaccine production to genetic signatures for ultra-early diagnosis.

In a small business solicitation released last week, the Army put out a call for “Multiagent Synthetic DNA Vaccines Delivered by Noninvasive Electroporation.” The program would start by transforming conventional development methods, like standard egg-based vaccines.

The old-school methods are slow, don’t allow for readily combined vaccines, and can pose sterility risks. DNA-based vaccines, on the other hand, would be quick to engineer and offer reliable immunity — provided the DNA can enter host cells to trigger the production of immunity proteins.

Right now, DNA-based vaccines are injected into muscles, meaning a genetically engineered plasmid is delivered to “intracellular spaces,” and “is not efficiently taken up by the host cells.” So the Army would instead like to shoot people. Seriously.

In its solicitation, the Army says it wants DNA vaccines that are painted onto microscopic beads, then “deposited into skin cells by gas propulsion.” And since that method can only inject a small dose of DNA, they want researchers to combine the approach with intramuscular electroporation, which “involves injecting the DNA then quickly applying short electrical pulses.” The electric charge creates pores in cell membranes, making it easier for DNA to enter targeted cells.

Sounds great, except that current approaches to intramuscular electroporation are invasive, and, obviously, they hurt. One study in rats also noted the “possibility of low and transient tissue damage induced by electroporation.” The Army wants a gadget that doesn’t rely on jamming needles and electrical pulses into muscle, and instead are after “injection and noninvasive electroporation [that] can be performe using a single integrated device.”

DNA-based vaccines are also still in their infancy: in 2005, the first-ever DNA vaccine for horses was approved, but human trials have yet to generate stellar results. And speaking of invasive: the Army’s delivery method of choice, gene guns, use helium gas to blast DNA into cells and often require surgically exposed muscle tissue to get the job done.

In other words, the Army’s asking for a non-invasive way to do what’s not yet possible, even using surgical methods. If researchers do come up with a device that meets the lofty criteria, though, it’d be just what the Pentagon’s looking for: a reliable way to engineer and deliver combination vaccines — not to mention a quick way to fight back against “unknown, emerging, or genetically engineered pathogens.”
Photo: Defense Link

Source: Wired,com
By: Katie Drummond, August 3, 2010