With the nation’s terror alert level raised to orange – or high – on Tuesday and evidence that al-Qaida may be planning another strike, fear of a biological terrorist threat is again running high.
Dr. Darrell Galloway, associate professor of microbiology and director of biological defense at the Naval Medical Research Center, has been researching the use of a DNA-based vaccine to immunize against anthrax or other pathogens – a vaccine which may prove safer and more effective than traditional vaccines.
“Anthrax is a toxin-mediated disease bacterium that, once it gets in the body, grows,” Galloway said. “It secretes three proteins as it grows and they can combine to produce toxins, causing the symptoms of anthrax,” Galloway said.
Anthrax is caused by the bacterium Bacillus anthracis.
“If we target the toxin proteins and neutralize them, we can prevent the physiological effects of anthrax,” Galloway said.
In traditional vaccines the actual pathogens or proteins produced by the disease itself, or some byproduct of it, are used to immunize. The immune system responds by making antibodies to neutralize the toxin. This involves a lot of work, time and expense to inject or prepare a vaccine, Galloway said.
The DNA-based vaccine provides cells with the target proteins needed to develop an immunity.
“We inject genes and individual cells. They make the vaccine on their own within the body,” Galloway said. “There are no side effects from preservatives normally in a vaccine.”
The current vaccine has a large number of complications, requiring several booster immunizations.
With the DNA-based vaccine, recipients “don’t have to boost as many times – it’s easier and cheaper,” said Mike Boehm, professor of plant pathology, who is also in the same Naval Reserve unit as Galloway.
The research started in conjunction with the U.S. Navy and Ohio State.
ViCal Incorporated, based in San Diego, holds the patent on the DNA-based vaccine, and Galloway was interested in their expertise.
“My lab and the Navy demonstrated proof of principle vaccine, so we expanded the project with ViCal,” Galloway said.
ViCal will take vaccine to human clinical trial. These initial trials are divided into phases. Phase I is a safety study where a few individuals are immunized. Here they look for indications of safety. Studies are usually conducted on volunteers from colleges.
“Its going to take several years for al the studies to be done. It depends on how aggressively the study is pushed,” Galloway said. “It will probably be two to five years to complete the study to the FDA’s satisfaction.”
Pending the FDA’s approval, ViCal will then choose whether to market it.
“They could sell it to the military, foreign governments or even the public,” Galloway said. “It depends on cost effectiveness – how it compares to the current vaccine.”
While anthrax is the particular area studied in Galloway’s research, the vaccine can be used on other pathogens.
“DNA vaccines show a lot of promise – this new approach is also being used experimentally for HIV and tuberculosis,” said Andrew Phipps, research scientist at the Batelle Memorial Institute. Phipps specializes in biodefense research.
These advancements in technology are the most important issue.
“DNA-based immunization can be effective is the key point here,” Galloway said. “If we show it works here, we can show it can work elsewhere.”
Anthrax was a way to get more attention and money for the research.
“It’s a novel approach to a hot topic,” Boehm said.
