Researchers Develop Effective Ebola Vaccine
http://abcnews.go.com/wire/US/reuters20030806_350.html
Aug. 6
— By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - U.S. government researchers said on Wednesday they had developed a vaccine that protected monkeys against Ebola virus with a single dose -- offering a new way to stop an outbreak of the deadly disease.
The vaccine was made using a new approach that should work against a range of other viruses, as well, the researchers said. And the new technology might offer a quick way to develop an instant vaccine against new infections, such as SARS, or even a biological weapon.
Dr. Gary Nabel, the top vaccine expert at the U.S. Institute of Allergy and Infectious Diseases and leader of the study, said he was surprised a single shot worked.
"If we can do this for Ebola virus, I am hopeful we can apply it to other infectious outbreaks," Nabel said in a telephone interview.
Ebola, a new and frightening virus that kills anywhere between 50 percent and 90 percent of victims though massive internal bleeding, has resisted vaccine efforts so far.
Nabel and colleagues started with a common virus called an adenovirus -- the culprit behind many cases of the common cold and some more serious infections as well. They added one piece of DNA from the Ebola virus -- the glycoprotein.
Traditional vaccines use a whole virus, live, killed or
weakened, to help the immune system recognize the invader. The DNA vaccine relies on a strong immune response to the adenovirus, and the immune system recognizes the Ebola virus simply by recognizing the glycoprotein.
To the researchers' surprise, monkeys given a single jab with this vaccine were 100 percent protected from what should have been a deadly dose of Ebola, they report in this week's issue of the journal Nature.
PROTECTING MORE THAN MICE
"After years of developing candidate Ebola vaccines that protected rodents but failed in primates, it is gratifying to have a vaccine that holds great promise for protection of humans," Peter Jahrling, a senior research scientist at the U.S. Army Research Institute of Infectious Diseases, who also worked on the study, said in a statement.
In April, an outbreak of Ebola killed more than 120 people in the Congo Republic and also killed many gorillas living in a nearby wildlife preserve. A vaccine would be used to control such outbreaks in both people and animals, Nabel said.
"Ring vaccination might be used to stop the spread of the Ebola virus during acute outbreaks, just as this strategy was used to contain smallpox in the past," Nabel said.
With ring vaccination, everyone who has been in contact with a patient, as well as all members of the patient's household, are vaccinated. It is also safer than the smallpox vaccine, which uses a live virus related to smallpox.
"This begins to change our minds about how vaccines can be used," Nabel said. Instead of vaccinating large populations against diseases just in case, such a vaccine could be used tactically, when an outbreak starts, to control it quickly.
Nabel said the approach may be used in the development of vaccine against SARS.
Severe Acute Respiratory Syndrome, which sickened more than 8,000 people around the world and killed more than 800, seems under control now but experts expect it could reemerge in the autumn. NIAID is working with Maryland-based GenVec on vaccines against both SARS and the AIDS virus.
For the Ebola virus, NIAID is working with Dutch biotechnology company Crucell NV. They hope to test it in humans soon.
NIAID is still pursuing an older approach to an Ebola vaccine that it has been working on with Merck and Co. Inc. called a DNA prime-boost, which may offer longer-term protection against the virus.
Copyright 2003 Reuters News Service. All rights reserved
http://abcnews.go.com/wire/US/reuters20030806_350.html
Aug. 6
— By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - U.S. government researchers said on Wednesday they had developed a vaccine that protected monkeys against Ebola virus with a single dose -- offering a new way to stop an outbreak of the deadly disease.
The vaccine was made using a new approach that should work against a range of other viruses, as well, the researchers said. And the new technology might offer a quick way to develop an instant vaccine against new infections, such as SARS, or even a biological weapon.
Dr. Gary Nabel, the top vaccine expert at the U.S. Institute of Allergy and Infectious Diseases and leader of the study, said he was surprised a single shot worked.
"If we can do this for Ebola virus, I am hopeful we can apply it to other infectious outbreaks," Nabel said in a telephone interview.
Ebola, a new and frightening virus that kills anywhere between 50 percent and 90 percent of victims though massive internal bleeding, has resisted vaccine efforts so far.
Nabel and colleagues started with a common virus called an adenovirus -- the culprit behind many cases of the common cold and some more serious infections as well. They added one piece of DNA from the Ebola virus -- the glycoprotein.
Traditional vaccines use a whole virus, live, killed or
weakened, to help the immune system recognize the invader. The DNA vaccine relies on a strong immune response to the adenovirus, and the immune system recognizes the Ebola virus simply by recognizing the glycoprotein.
To the researchers' surprise, monkeys given a single jab with this vaccine were 100 percent protected from what should have been a deadly dose of Ebola, they report in this week's issue of the journal Nature.
PROTECTING MORE THAN MICE
"After years of developing candidate Ebola vaccines that protected rodents but failed in primates, it is gratifying to have a vaccine that holds great promise for protection of humans," Peter Jahrling, a senior research scientist at the U.S. Army Research Institute of Infectious Diseases, who also worked on the study, said in a statement.
In April, an outbreak of Ebola killed more than 120 people in the Congo Republic and also killed many gorillas living in a nearby wildlife preserve. A vaccine would be used to control such outbreaks in both people and animals, Nabel said.
"Ring vaccination might be used to stop the spread of the Ebola virus during acute outbreaks, just as this strategy was used to contain smallpox in the past," Nabel said.
With ring vaccination, everyone who has been in contact with a patient, as well as all members of the patient's household, are vaccinated. It is also safer than the smallpox vaccine, which uses a live virus related to smallpox.
"This begins to change our minds about how vaccines can be used," Nabel said. Instead of vaccinating large populations against diseases just in case, such a vaccine could be used tactically, when an outbreak starts, to control it quickly.
Nabel said the approach may be used in the development of vaccine against SARS.
Severe Acute Respiratory Syndrome, which sickened more than 8,000 people around the world and killed more than 800, seems under control now but experts expect it could reemerge in the autumn. NIAID is working with Maryland-based GenVec on vaccines against both SARS and the AIDS virus.
For the Ebola virus, NIAID is working with Dutch biotechnology company Crucell NV. They hope to test it in humans soon.
NIAID is still pursuing an older approach to an Ebola vaccine that it has been working on with Merck and Co. Inc. called a DNA prime-boost, which may offer longer-term protection against the virus.
Copyright 2003 Reuters News Service. All rights reserved
