Experimental anthrax vaccine is needle-free
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By Maggie Fox, Health and Science Editor
WASHINGTON (Reuters) - An experimental anthrax vaccine can be squirted up the nose and might be easier to distribute than the current multishot regime, U.S. researchers reported on Friday.
The new vaccine protected guinea pigs against inhaled anthrax, considered the most dangerous form, the team at the University of Michigan Medical School and the University of Texas Medical Branch in Galveston reported.
Writing in the August issue of Infection and Immunity, Michigan's Dr. James Baker and colleagues said the secret was the adjuvant -- a compound commonly added to vaccines to make them stimulate the immune system more effectively.
The adjuvant might be used to make other vaccines more effective and more stable as well, Baker said in a telephone interview.
Their adjuvant was invented at the university and licensed to privately owned, Ann Arbor, Michigan-based NanoBio Corp. It is an oil-and-water emulsion that helps get the main vaccine ingredients into the body's immune cells.
"It is unique in that it doesn't induce an inflammatory response. What we think it does is that it actually induces delivery of the antigen," Baker said.
It apparently helps deliver the antigen -- the part of the anthrax bacteria that the immune system is supposed to recognize -- across the mucosal tissue of the nose and straight into immune cells called dendritic cells, Baker said.
Vaccines are meant to help the immune system recognize invaders such as bacteria and viruses more easily.
This one uses a single protein from the anthrax bacteria and does not cause the inflammation and irritation associated with current anthrax vaccines.
The current anthrax vaccine, given to most members of the U.S. military, is based on a 30-year-old formula and uses alum as an adjuvant. It is irritating and causes side effects and, worst of all, people need six doses and annual boosters.
LONG-TERM PROTECTION
The new vaccine protected guinea pigs after just two doses, Baker's team reported.
"We got protection after only two administrations that was good for six months after immunization," Baker said. "So it is really better than the current vaccine."
Anthrax is found naturally around the world and usually only infects animals and their handlers. It mostly causes a skin infection in people that is easily treated with antibiotics.
But the powdered spores can be inhaled and cause a hard-to-recognize infection, making anthrax an ideal biological weapon.
In October 2001, five people died out of 22 infected after someone mailed letters containing finely milled anthrax spores to New York and Washington in a crime that has never been solved.
Baker said his team must wait for U.S. government contracts to move ahead with human studies of the anthrax vaccine.
But they are using the approach for other vaccines, he said, including a hepatitis B vaccine for the developing world, funded by the Bill and Melinda Gates Foundation.
"We have got proof of concept in several other vaccines," Baker said. "By mixing antigen with the emulsion, it actually stabilizes it."
That means the vaccine can be transported with no refrigeration.
By Maggie Fox, Health and Science Editor
WASHINGTON (Reuters) - An experimental anthrax vaccine can be squirted up the nose and might be easier to distribute than the current multishot regime, U.S. researchers reported on Friday.
The new vaccine protected guinea pigs against inhaled anthrax, considered the most dangerous form, the team at the University of Michigan Medical School and the University of Texas Medical Branch in Galveston reported.
Writing in the August issue of Infection and Immunity, Michigan's Dr. James Baker and colleagues said the secret was the adjuvant -- a compound commonly added to vaccines to make them stimulate the immune system more effectively.
The adjuvant might be used to make other vaccines more effective and more stable as well, Baker said in a telephone interview.
Their adjuvant was invented at the university and licensed to privately owned, Ann Arbor, Michigan-based NanoBio Corp. It is an oil-and-water emulsion that helps get the main vaccine ingredients into the body's immune cells.
"It is unique in that it doesn't induce an inflammatory response. What we think it does is that it actually induces delivery of the antigen," Baker said.
It apparently helps deliver the antigen -- the part of the anthrax bacteria that the immune system is supposed to recognize -- across the mucosal tissue of the nose and straight into immune cells called dendritic cells, Baker said.
Vaccines are meant to help the immune system recognize invaders such as bacteria and viruses more easily.
This one uses a single protein from the anthrax bacteria and does not cause the inflammation and irritation associated with current anthrax vaccines.
The current anthrax vaccine, given to most members of the U.S. military, is based on a 30-year-old formula and uses alum as an adjuvant. It is irritating and causes side effects and, worst of all, people need six doses and annual boosters.
LONG-TERM PROTECTION
The new vaccine protected guinea pigs after just two doses, Baker's team reported.
"We got protection after only two administrations that was good for six months after immunization," Baker said. "So it is really better than the current vaccine."
Anthrax is found naturally around the world and usually only infects animals and their handlers. It mostly causes a skin infection in people that is easily treated with antibiotics.
But the powdered spores can be inhaled and cause a hard-to-recognize infection, making anthrax an ideal biological weapon.
In October 2001, five people died out of 22 infected after someone mailed letters containing finely milled anthrax spores to New York and Washington in a crime that has never been solved.
Baker said his team must wait for U.S. government contracts to move ahead with human studies of the anthrax vaccine.
But they are using the approach for other vaccines, he said, including a hepatitis B vaccine for the developing world, funded by the Bill and Melinda Gates Foundation.
"We have got proof of concept in several other vaccines," Baker said. "By mixing antigen with the emulsion, it actually stabilizes it."
That means the vaccine can be transported with no refrigeration.
