A virus called GB Virus-C has, apparently, infected more than a billion people alive today. But, fortunately, the cost of being infected with this virus is so low that researchers don’t think it causes any illness. In fact, it might stave them off, reports NPR's Richard Harris.
GBV-C infects white blood cells and dampens the body’s immune response. "It's not severe — it's not enough that it makes people immune-suppressed," Jack Stapleton, an infectious disease specialist at the University of Iowa, told NPR, "but it does reduce the inflammatory response of immune cells." The virus can be transmitted sexually, through blood and from an infected mother.
All this resembles HIV, and, in fact, people infected with HIV are also likely to have GBV-C. But that might be a good thing. Some studies have shown that GBV-C slows the progression of HIV infection.
Researchers don’t know exactly how GBV-C could do that, but they suspect that the virus reduces inflammation and thus staves off AIDS. If that’s the mechanism, it might also work in other viral diseases — say, Ebola. Though the number of new cases this month in the worst-affected countries was the lowest since late June, the Red Cross says the virus is appearing in new regions and that West Africa may not be rid of it this year.
Hypothetically, this virus might also reduce inflammation in some people fighting off a roaring Ebola infection. "It's something you would predict," Stapleton says. "Although often what you predict doesn't happen, so I wouldn't have predicted it." But if that's the case, perhaps drugs that act in a similar manner would help as well.
The idea isn’t just theoretical. A study last summer that gathered plasma from Ebola patients in order to study the genetics of Ebola viruses also yielded some information about GBV-C. A pathologist, David O’Connor of the University of Wisconsin in Madison, found 13 samples from people who had both Ebola and GBV-C. Six of those people died, but seven survived. Given that the death rate in this latest outbreak has been 70 percent, that's a notable outcome. The work is published in the Journal of Virology.
It may be that the co-infection slowed Ebola’s progression, just as it does HIV’s, and gave the people a chance to fight off the deadly virus. But larger numbers would be needed to state that with any certainty. Still, while O’Connor is cautious about these results, he could see a future where it might be worth testing deliberate infection with GBV-C. "The thinking is," he told NPR, "this infects hundreds of millions of people around the world today; we knowingly transmit it in blood transfusions. It's essentially a safe virus."
We think. Another study has found that the virus might be more common in people with non-Hodgkin lymphoma, raising the possibility that GBV-C could be connected with some negative health effects. Again, that association isn’t strong enough to say much for sure. But it is worth seeing if GBV-C is as good as it seems.