U.S. Army Scientists Exploring DNA Vaccines

U.S. Army scientists are studying a new DNA vaccine-delivery method that is needle-free and painless, said a senior Army research scientist at Fort Detrick, Md.

One of the newest DNA vaccine-delivery methods relies on technology known as the “gene gun,” which is capable of delivering the vaccine directly into cells. This needle-free vaccination method is more cost-effective, and it’s less painful for the recipient.

“DNA offers a number of advantages over conventional vaccine approaches, especially with regard to biodefense vaccines. This is important when rapid vaccine development is needed for a newly emerging disease threat or possibly for a genetically engineered biological warfare pathogen,” Dr. Connie Schmaljohn, senior research scientist at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) told “Armed with Science: Research and Applications for the Modern Military” listeners during a live audio webcast on May 27.

USAMRIID is currently conducting a human study of DNA vaccines using this delivery method. Schmaljohn’s research team has isolated small amounts of DNA from the Hantaan and Puumala viruses to develop the vaccines. These particular viruses are known health threats to U.S. troops stationed in Europe and Asia. Both vaccines are now in Phase I clinical testing, the first step toward licensure by the U.S. Food and Drug Administration.

“The DNA is first coated onto very, very tiny gold beads, and those gold beads with the DNA are then put inside of a plastic device that’s about the size of a small flashlight. Inside that device is also a little canister of compressed helium gas,” Schmaljohn explained. “When the trigger of the gene gun device is pushed, the gas is released and it propels the gold [bead] coated with the DNA out of the device [and] into the skin of the vaccine recipient.”

USAMRIID is producing a DNA vaccine for the Asian and European hantaviruses that can cause hemorrhagic fever with renal syndrome. This disease was first recognized as a threat during the Korean War.

“The hantaviruses, once they infect humans, can cause one of two serious human illnesses – hemorrhagic fever with renal syndrome, which occurs in Asia and Europe — or hantavirus pulmonary syndrome, which occurs in the Americas,” Schmaljohn said. “Today there’s more than 100,000 cases of hemorrhagic fever with renal syndrome each year, with the highest number occurring in China, Russia…Scandinavia and other parts of Europe.”

These viruses are found in many types of rodents, including rats, field mice, and meadow voles.
http://www.dodlive.mil/index.php/2009/06/us-army-scientists-exploring-dna-vaccines/