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Many in West Africa May Be Immune to Ebola Virus
By DONALD G. McNEIL Jr.SEPT. 5, 2014
Although few medical experts realize it, part of the population in West Africa is immune to the Ebola virus, according to virologists who specialize in the disease.
Assuming they are correct, and if those people can be identified, they could be a great help in fighting the outbreak. Immune persons could safely tend the sick and bury the dead just as smallpox survivors did in the centuries before smallpox vaccine.
Also, antibodies could be harvested from their blood to treat new Ebola victims.
...
?It?s fair to say that some people are immune,? said Robert F. Garry Jr., a Tulane University expert in hemorrhagic fevers who works in Sierra Leone. ?But we don?t know if it?s 1 percent or 2 percent or 20 percent.?
...
Right now, there are about 1,800 survivors of the current West African outbreak, all of whom are now immune, of course. But there may be many thousands more.
Small studies of household contacts of Ebola victims show that some people are infected without ever falling ill ? perhaps because of some unknown genetic advantage.
But many Africans who have never seen a victim also have antibodies.
It is possible that some get low doses of virus by eating infected monkeys or bats that are undercooked.
...
One of France?s leading Ebola experts says he believes that many rural villagers are ?vaccinated? by eating fruit gnawed on by bats and contaminated with their saliva.
?We imagine that this is the main route,? said Dr. Eric M. Leroy, a veterinarian and virologist at the International Center for Medical Research in Franceville, Gabon. ?But it is a hypothesis. We do not have the evidence.?
...
?I don?t think we have a good idea of what constitutes a person who?s going to survive versus a person who?s going to succumb,? said Randal J. Schoepp, head of diagnostics at the United States Army Medical Research Institute of Infectious Diseases in Fort Detrick, Md., who led a study of blood from patients in a Sierra Leone hospital who were originally thought to have Lassa fever but did not. Nearly 9 percent had Ebola antibodies ? and the samples dated from as far back as 2006, proving that the virus circulated long before this year?s outbreak.
Also, there is anecdotal evidence that some West Africans are resistant. Victims have relatives who never get sick. At the funeral of a traditional healer where 14 women became infected, at least 26 other mourners did not, Dr. Garry said, even though most probably touched the body.
...
Those who are immune can donate blood containing antibodies to be given to acutely ill patients, as was done for Dr. Kent Brantly, one of the first two Americans to get Ebola. He survived, although his Emory University doctors later said it was unclear whether the transfusion or an experimental drug, ZMapp, containing cloned antibodies, helped him at all.
Having those who are immune be caregivers and body carriers makes sense, said Tom Skinner, a spokesman for the Centers for Disease Control and Prevention.
?But we can?t count on their immunity,? he added. ?They would still need full personal protective gear.?
Relying on such measures may be inevitable, Dr. Garry said, adding:
?There?s no more ZMapp out there. It?s time for creative solutions.?
http://www.nytimes.com/2014/09/06/health/ebola-immunity.html?_r=0
By DONALD G. McNEIL Jr.SEPT. 5, 2014
Although few medical experts realize it, part of the population in West Africa is immune to the Ebola virus, according to virologists who specialize in the disease.
Assuming they are correct, and if those people can be identified, they could be a great help in fighting the outbreak. Immune persons could safely tend the sick and bury the dead just as smallpox survivors did in the centuries before smallpox vaccine.
Also, antibodies could be harvested from their blood to treat new Ebola victims.
...
?It?s fair to say that some people are immune,? said Robert F. Garry Jr., a Tulane University expert in hemorrhagic fevers who works in Sierra Leone. ?But we don?t know if it?s 1 percent or 2 percent or 20 percent.?
...
Right now, there are about 1,800 survivors of the current West African outbreak, all of whom are now immune, of course. But there may be many thousands more.
Small studies of household contacts of Ebola victims show that some people are infected without ever falling ill ? perhaps because of some unknown genetic advantage.
But many Africans who have never seen a victim also have antibodies.
It is possible that some get low doses of virus by eating infected monkeys or bats that are undercooked.
...
One of France?s leading Ebola experts says he believes that many rural villagers are ?vaccinated? by eating fruit gnawed on by bats and contaminated with their saliva.
?We imagine that this is the main route,? said Dr. Eric M. Leroy, a veterinarian and virologist at the International Center for Medical Research in Franceville, Gabon. ?But it is a hypothesis. We do not have the evidence.?
...
?I don?t think we have a good idea of what constitutes a person who?s going to survive versus a person who?s going to succumb,? said Randal J. Schoepp, head of diagnostics at the United States Army Medical Research Institute of Infectious Diseases in Fort Detrick, Md., who led a study of blood from patients in a Sierra Leone hospital who were originally thought to have Lassa fever but did not. Nearly 9 percent had Ebola antibodies ? and the samples dated from as far back as 2006, proving that the virus circulated long before this year?s outbreak.
Also, there is anecdotal evidence that some West Africans are resistant. Victims have relatives who never get sick. At the funeral of a traditional healer where 14 women became infected, at least 26 other mourners did not, Dr. Garry said, even though most probably touched the body.
...
Those who are immune can donate blood containing antibodies to be given to acutely ill patients, as was done for Dr. Kent Brantly, one of the first two Americans to get Ebola. He survived, although his Emory University doctors later said it was unclear whether the transfusion or an experimental drug, ZMapp, containing cloned antibodies, helped him at all.
Having those who are immune be caregivers and body carriers makes sense, said Tom Skinner, a spokesman for the Centers for Disease Control and Prevention.
?But we can?t count on their immunity,? he added. ?They would still need full personal protective gear.?
Relying on such measures may be inevitable, Dr. Garry said, adding:
?There?s no more ZMapp out there. It?s time for creative solutions.?
http://www.nytimes.com/2014/09/06/health/ebola-immunity.html?_r=0