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New Anthrax Vaccine???

 
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arizroughrider
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PostPosted: Mon Jan 24, 2005 10:31 pm    Post subject: New Anthrax Vaccine??? Reply with quote

Contact: Jonathan Weil
(212) 821-0560
jweil@med.cornell.edu
Sean Kelliher
sbk2001@med.cornell.edu



Weill Cornell team develops fast-acting anthrax vaccine
NEW YORK (December 29, 2004) -- In any bioterror attack, vaccines that provide a rapid, effective defense against the pathogen will be key to saving lives.
However, in the case of anthrax, vaccines available today can take weeks or even months to gain full effect.

Research underway at Weill Cornell Medical College in New York City may provide health officials with a much quicker option. Using gene transfer technology, investigators here were able to immunize mice against anthrax in just 12 hours.

"That's important, because in the event of an attack, those in charge won't necessarily know whether another attack is coming -- or who might be affected. In that case, you want immunity to be built up in key populations as quickly as possible," said Dr. Ronald G. Crystal, Chairman of the Department of Genetic Medicine, Weill Cornell Medical College, and Chief of the Division of Pulmonary and Critical Care Medicine, NewYork-Presbyterian Hospital/Weill Cornell Medical Center.

His team's findings will be published in the February issue of Molecular Therapy.

According to Dr. Crystal, vaccines tend to fall into one of two groups -- active vaccines, where the body is prompted over time to build up antibodies against specific threats; and passive vaccines, where fully-formed antibodies are delivered to the body in vaccine form.

"Because the body continues to produce antibodies, active vaccines last much longer than the passive kind, whose effectiveness tend to diminish over time," he explained.

But active vaccines have one major drawback: they need lots of time to develop. For example, the anthrax vaccine provided to U.S. Army troops following the 2001 attacks requires that troops receive six doses stretched over 18 months.

Populations threatened by the sudden dispersal of deadly anthrax spores won't have the luxury of that much time. So Dr. Crystal and his team turned their attention to faster-acting passive vaccines instead.

"We looked especially at the use of gene transfer technology -- introducing genes that can manufacture antibodies against key components of the anthrax toxin," he said.

Genes need a live means of entering the body, however, so Dr. Crystal's team incorporated the gene within a harmless organism called an adenovirus.

Once inside the mouse's body, the gene began producing an immune-system antibody targeted to a key component of the deadly anthrax toxin.

"The adenovirus delivers the gene to the mouse, and then the gene goes to work -- telling the animal's body to make this antibody against anthrax," Dr. Crystal said.

The result?...

"Mice were immune to anthrax within 12 to 18 hours of vaccination," he said. "Compared to other vaccine technologies, this gene transfer strategy works very quickly."

While gene transfer has been used to deliver antibodies in other clinical settings, "to our knowledge this is the first time it's been used as a strategy against bioterrorism," Dr. Crystal said.

Of course, many hurdles remain before this type of vaccine might be ready for public use. Because humans are so much bigger than mice, dosing issues remain. It might also take two or more years of testing in animal models before the vaccine is deemed safe enough to test in humans.

Passive vaccines might never fully replace active varieties, Dr. Crystal said. In fact, the new vaccine will probably work best when used in combination with an active vaccine.

"Remember, passive vaccines like this one can lose their effectiveness over time, whereas active vaccines do not," Dr. Crystal explained. "We're now developing a strategy where we might give people both the active and passive vaccine. With the passive vaccine you'd get protection that would last a couple of weeks, but that would give you a safety margin while your body is developing more active, long-term immunity."

The research was supported, in part, by a Gift from Robert A. Belfer to Support Development of an Antibioterrorism Vaccine, and by the Will Rogers Memorial Fund (Los Angeles, CA).

Co-researchers included Dr. Kazuhiko Kasuya, Dr. Julie Boyer, and Dr. Yadi Tan of the Department of Genetic Medicine at Weill Cornell Medical College; and Dr. Neil R. Hackett and D. Olivier Alipui of the Belfer Gene Therapy Core Faculty at Weill Cornell.

# # #

Office of Public Affairs Joan and Sanford I. Weill Medical College of Cornell University 525 East 68th Street, Box 144 New York, NY 10021

-30-

|December release index | | Cornell News Service Home Page |
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Gary M - Author
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PostPosted: Tue Jan 25, 2005 5:17 am    Post subject: Reply to "arizroughrider"; RE: New Anthrax Vaccine Reply with quote

Dear "arizroughrider": There are lots of new anthrax vaccines being developed to replace the old one. The leading candidate, rPA102, is the one the Army designed. The White House already has bought 75 million doses of it ... even though it's still unlicensed. In the event of a bioterrorism attack with anthrax, the new vaccine, license or no license, will be given to civilians living and working in an affected area.

The question is whether it will really do a better job of protecting people.

Anthrax Vaccines Without Anthrax
If you take squalene out of the new vaccine, it is virtually identical to the old one. Both are "acellular." In other words they contain no anthrax cells. They are made from a single protein secreted by the organism called protective antigen.

Because these vaccines contain no anthrax, not even pieces of it, they do not promote the clearance of the organism, or its spores, from the body. This is what makes PA vaccines so weak. It is also why Army scientists suspect the licensed vaccine won't work.

This not a state secret, and at Fort Detrick, at least, it is not news. Starting in the early 1960s, some of the Army's top biodefense scientists at Fort Detrick argued that the design of the Army's anthrax vaccine made no sense. There was, they wrote:

Quote:
"...no experimental basis for selection or use of a single antigen for immunizing man, domestic or experimental animals. Indeed all evidence is contrary to this practice."

Mahlandt BG, Klein F, Lincoln RE, Haines BW, Jones WI Jr., Friedman RH, Immunologic Studies of Anthrax IV. Evaluation of the Immunogenicity of Three Components of Anthrax Toxin, The Journal of Immunology, 1966 Apr;96(4): pg. 732.


Both U.S. and British Army scientists reached the same conclusions in the 1980s, but the U.S. Army chose to stick with its original design — a vaccine based on a single protein, protective antigen — when it developed the second generation vaccine. The new vaccine is just a PA vaccine made with 1990s, instead of 1950s, technology.

Recognizing how illogical all this is, many of the scientists working on new anthrax vaccines have added anthrax "sub-units" (parts of the organism) or even killed whole spores to a PA preparation.

Anthrax Vaccines That Contain Some Anthrax
Harvard Medical School has developed a "bi-valent" anthrax vaccine, which means it promotes an immune response to two things. There's PA in the vaccine, but Harvard's concoction also promotes an immune response to the germ's acid capsule, which is what inhibits the germ's destruction by immune cells.

The Pasteur Institute in Paris — named after the creator of the world's first anthrax vaccine, Louis Pasteur — has developed a vaccine, which combines PA with anthrax spores killed with formaldehyde. This vaccine promotes an immune response to anthrax spores in addition to PA.

The State Research Institute of Applied Microbiology in Obolensk outside of Moscow developed a living vaccine made from the Russian STI-1 strain. This vaccine promotes comprehensive immunity against the anthrax toxin proteins, the cell surface, spores and the capsule. It is widely regarded to be the most effective anthrax vaccine in the world.

The Cornell University Medical School vaccine is what immunologists call a "live vector" vaccine. Cornell's scientists inserted anthrax DNA into the genome of a virus. When you splice DNA from one organism into another, the resulting hybrid is called a "chimera." When the immune system responds to virus, it also responds to its extra genetic baggage — the anthrax DNA.

According to the press release from Cornell Medical School, the host organism — in this case, adenovirus — won't get anyone sick.

Quote:
"... Dr. Crystal's team incorporated the gene within a harmless organism called an adenovirus."


But this is what the CDC has to say about the supposedly "harmless" adenovirus.

Quote:
"Adenoviruses most commonly cause respiratory illness; however, depending on the infecting serotype, they may also cause various other illnesses, such as gastroenteritis, conjunctivitis, cystitis, and rash illness. Symptoms of respiratory illness caused by adenovirus infection range from the common cold syndrome to pneumonia, croup, and bronchitis. Patients with compromised immune systems are especially susceptible to severe complications of adenovirus infection. Acute respiratory disease (ARD), first recognized among military recruits during World War II, can be caused by adenovirus infections during conditions of crowding and stress."

http://www.cdc.gov/ncidod/dvrd/revb/respiratory/eadfeat.htm

The Looking Glass
The Army says it has a 100% effective anthrax vaccine that it has been trying to replace for more than 20 years, in part, because Army scientists really suspect it's not so effective.

Cornell Med School says it's got a new fangled anthrax vaccine made from a harmless virus that the CDC doesn't consider so harmless.

When FDA scientists found 10 to 83 ppb squalene in anthrax vaccine, a longtime Army subcontrator, Stanford Research International (SRI) —knowing the FDA found squalene in concentrations no greater than 83 ppb — created a test that could only detect squalene concentrations above 140 ppb. {Spanggord RJ, Wu B, Sun M, Lim P, Ellis WY, Development and application of an analytical method for the determination of squalene in formulations of anthrax vaccine adsorbed, J of Pharm Biomed Anal. 2002 Jun 20;29(1-2):183-93.}

SRI's test then, by design, cannot find what the FDA found.

Not surprisingly, SRI says that based on its test, there is no squalene in anthrax vaccine.

Sincerely,
Gary Matsumoto
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