While the Ebola virus infects and kills thousands, it may also be silently building up a natural immunity in some people. It was already believed that survivors of Ebola like Mark Jerry and Zaizay Mulbah – pictured above before their shift working with Doctors Without Borders – have developed antibodies to Ebola and are probably immune once healed. Still, some people exposed to Ebola in Africa appear to have never been infected and may be naturally immune, according to a letter published in The Lancet.
The letter was co-authored by researchers in the Department of Integrative Biology at The University of Texas at Austin. Not only is it exciting to think that some people may be naturally immune to the virus, but the implications of natural immunity are huge when it comes to controlling the spread of the virus, Medical News Today explained. Projections of the toll that the Ebola virus will have on humanity do not include adjustments based on the possibility that some people may be immune. That’s good news, according to Medical News Today.
“There is limited evidence from past outbreaks that suggests there probably are quite a few people who get exposed, who get infected, without ever developing symptoms and without ever developing illness, but they develop immunity,” said researcher Lauren Ancel Meyers. The letter explains that there could be large numbers of people in West Africa who are exposed to Ebola, but never get sick. Because Ebola is only contagious after the incubation period, these immune people would not infect others and may be protected from Ebola infections in the future.
Immune individuals, once identified, could be recruited to help with disease control and healthcare, which would reduce exposure to those presumed not immune to Ebola, Dr. Steve Bellan explained.
“Recruitment of such individuals might be preferable to enlistment of survivors of symptomatic Ebola disease, because survivors might experience psychological trauma or stigmatization and be fewer in number – in view of the asymptomatic proportions suggested in previous studies and the low survival rate of symptomatic cases,” the letter in The Lancet explained.
Even in survivors, being immune is only presumed. It’s not a proven fact. Will Pooley, the healthcare worker who survived Ebola, was told he was still potentially at risk.
“They have told me I very likely have immunity, at least for the near future, to this strain of Ebola. I have also been told it’s a possibility that I don’t, so I will just have to act as if I don’t,” Pooley told The Guardian.
The best evidence that some people may be immune to Ebola is research that was done in 1996 during an Ebola outbreak. Researchers monitored two dozen contacts of known Ebola patients. These study participants never got sick even though they were in close contact with patients. Eleven of those monitored ended up having antibodies to Ebola, but they had never been ill.
“If this turns out to be true, there is widespread silent Ebola infection that is immunizing,” Meyers said of the possibility that some people may be immune. “We should really investigate it further.”
It’s not unheard of for some people to be naturally immune to devastating diseases. In Peru, one in ten people in a study appeared to have survived rabies, which is a virus that was believed to be 100 percent fatal. Earlier this year, reports announced that researchers discovered rare immunity to malaria in six percent of children they studied in Tanzania.
The probability is that there are unidentified people out there who are immune to Ebola. People immune to Ebola could be extremely helpful at reducing the anticipated spread if they are able to be identified, the authors of the letter explained.
[Photo by John Moore/Getty Images via Baltimore Sun]