Featured Research

from universities, journals, and other organizations

Vaccination With Anthrax Capsule Protects Against Experimental Infection In Animals

Date:
December 2, 2004
Source:
U.S. Army Medical Research Institute Of Infectious Diseases
Summary:
Vaccination with the anthrax capsule, a naturally occurring component of the bacterium that causes the disease, protected mice from lethal anthrax infection, according to scientists at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID).

Anthrax spores.
Credit: Image courtesy of NASA

Vaccination with the anthrax capsule, a naturally occurring component of the bacterium that causes the disease, protected mice from lethal anthrax infection, according to scientists at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID). In addition, the capsule enhanced the effects of protective antigen (PA), the protective component of the current licensed human vaccine. The work was recently published in the journal VACCINE.

According to senior author Arthur M. Friedlander, M.D., Bacillus anthracis, the causative agent of anthrax, produces three main components that allow it to do harm--lethal toxin, edema toxin, and the capsule. During anthrax infection, the bacterium invades and grows to high concentrations in the host. The capsule surrounds the bacterium and prevents it from being ingested by host white blood cells that would otherwise destroy it, thus allowing anthrax infection to progress. The toxins are thought to act mainly by damaging defensive cells called phagocytes, causing the immune system to malfunction.

The efficacy of the current licensed anthrax vaccine, Anthrax Vaccine Adsorbed (AVA), is believed to be based on the presence of PA. Though the exact mechanism of protection is not known, antibodies to PA induced by AVA are believed to play a role in neutralizing the anthrax toxins.

USAMRIID scientists have extensively studied protective antigen, demonstrating that PA alone confers protection in animal challenge studies with both rabbits and nonhuman primates. In addition, the recombinant, highly purified version of PA developed and tested by the Institute is the basis for a next generation anthrax vaccine currently in advanced development.

However, because a response against PA is thought to target the toxins only, there is interest in identifying additional potential anthrax vaccine components that target the whole organism. According to Friedlander, scientists have suspected for some time that the anthrax capsule plays a role in conferring protection. This study provides the first definitive proof of that concept.

The research team vaccinated several groups of mice. One month after the second dose, the mice were challenged with lethal doses of spores from a strain of anthrax producing only the capsule. In the group that had received the capsule vaccine, 7 of 12 mice survived challenge. In the control group, which received injections of a placebo instead of the capsule vaccine, none of the 12 mice survived.

Next, the team evaluated the efficacy of capsule vaccines alone or in combination with PA, using the same dosage schedule as before. In this experiment, using a fully virulent strain producing both capsule and toxins, neither capsule nor PA alone protected while the combination vaccine resulted in survival of 9 of 11 mice.

"We demonstrated that protection was even greater when the capsule was combined with PA, compared to when PA was given alone," Friedlander said. "A different formulation could make it even better. The next step will be testing in additional animal models."

Friedlander's colleagues on the study were Donald J. Chabot, Angelo Scorpio, Steven A. Tobery, Stephen F. Little, and Sarah L. Norris.

"This work shows the importance of developing vaccines that target multiple agent-specific targets," said George V. Ludwig, Ph.D., interim science director for USAMRIID. "This helps reduce the possibility of technological surprise when dealing with emerging biological threats."###

USAMRIID, located at Fort Detrick, Maryland, is the lead medical research laboratory for the U.S. Biological Defense Research Program, and plays a key role in national defense and in infectious disease research. The Institute's mission is to conduct basic and applied research on biological threats resulting in medical solutions (such as vaccines, drugs and diagnostics) to protect the warfighter. USAMRIID is a subordinate laboratory of the U.S. Army Medical Research and Materiel Command.

References:

Donald J. Chabot, Angelo Scorpio, Steven A. Tobery, Stephen F. Little, Sarah L. Norris, Arthur M. Friedlander. Anthrax capsule vaccine protects against experimental infection. Vaccine 23. 1:43-47 (2004).

For more information about USAMRIID: http://www.usamriid.army.mil


Story Source:

The above story is based on materials provided by U.S. Army Medical Research Institute Of Infectious Diseases. Note: Materials may be edited for content and length.


Cite This Page:

U.S. Army Medical Research Institute Of Infectious Diseases. "Vaccination With Anthrax Capsule Protects Against Experimental Infection In Animals." ScienceDaily. ScienceDaily, 2 December 2004. <www.sciencedaily.com/releases/2004/12/041201144858.htm>.
U.S. Army Medical Research Institute Of Infectious Diseases. (2004, December 2). Vaccination With Anthrax Capsule Protects Against Experimental Infection In Animals. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2004/12/041201144858.htm
U.S. Army Medical Research Institute Of Infectious Diseases. "Vaccination With Anthrax Capsule Protects Against Experimental Infection In Animals." ScienceDaily. www.sciencedaily.com/releases/2004/12/041201144858.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
West Africa Gripped by Deadly Ebola Outbreak

West Africa Gripped by Deadly Ebola Outbreak

AFP (July 28, 2014) The worst-ever outbreak of the deadly Ebola epidemic grips west Africa, killing hundreds. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins