Compared to that epidemic, “the DRC’s outbreaks have been smaller and more isolated,” says Anne Rimoin at the University of California, Los Angeles, “and so too have these survivors. They’ve had no contact or follow-up.” They still bear the scars and social stigma of their experience with the virus. But they also carry defenses against it.
Rimoin has shown that the original survivors’ blood still contains antibodies against Ebola. In some cases, people had antibodies that can destroy the virus outright, even after 41 years. “They should be immune to Ebola,” Rimoin says.
Simply finding the survivors was a Herculean task. Medical records from that 1976 outbreak were nowhere to be found, so Rimoin had to ask the researchers who were on the scene to rummage through their files. Once she had a list, her team took several trips to Yambuku to search for the people behind the names. And since the town is so remote, every trip involved a chartered flight and a grueling drive. “It took maybe 9 hours in the dry season, and 20 hours in the rainy season,” Rimoin says.
The team eventually tracked down 14 survivors who, according to Rimoin, were eager to take part in a new study. “They were very happy that there were people out there interested in hearing their stories and understanding what they had been through,” she says. “It may have been a long time ago, but they are still living the consequences of what they’ve suffered. Most of them lost family members. And when they emerged from the hospital, having narrowly survived a terrifying near-death experience, they found their homes had been burned to the ground for fear of contamination. Everything they owned had disappeared.”
Even now, they have to live with the social stigma of having once had Ebola four decades ago. Such is the fear surrounding the virus that the hospital in Yambuku was initially reluctant to let Rimoin bring her volunteers in to take blood samples. “To this day, if you say you’re an Ebola survivor, people will recoil,” she says.
Previously, another team found that Ebola patients retain some immunity against the virus after 14 years, but Rimoin’s team have shown that this protection extends for decades more. All of the 14 people they studied still carry antibodies that recognize at least one of the Ebola virus’s proteins, and four had antibodies that could completely neutralize the virus. “Those are the kinds of responses you’d like to see in a vaccine—long-lasting and robust,” says Rimoin, “which means that these antibodies are of great value to science.”
It’s clear that the Ebola virus can stick around long after symptoms abate, by hiding out in unusual places like eyeballs. One man still carried the virus in his semen 565 days after he recovered. Ebola’s tenacity might explain why survivors continue to produce antibodies against it, long after they’ve finally cleared it from their bodies.