When the human body outwits a deadly virus
With humankind focused on surviving the SARS-CoV-2 virus, I find it oddly reassuring to think about other deadly foes we’ve faced. Some, like the virus that caused the 1918 influenza pandemic, waned as people developed immunity. Others, like HIV, continue to threaten, killing 690,000 people worldwide last year.
It’s been more than 40 years since doctors in the United States started seeing young men become terribly ill with rare cancers and pneumonia. In 1982, these mysterious infections were given a name: acquired immune deficiency syndrome, or AIDS. In 1983, human immunodeficiency virus, or HIV, was identified as the culprit.
I’m old enough to remember when having AIDS was a death sentence. I saw friends suffer and die. Now, antiretroviral drugs can help keep infected people healthy for many years, reducing the amount of virus in their bodies to levels too low to infect others. And medications can protect people from getting infected in the first place (SN: 11/23/19, p. 16). We haven’t vanquished HIV, but decades of effort by scientists around the world has substantially reduced HIV’s toll, and changed our view of the disease from hopeless to manageable.
In this issue, we report on a study that reveals a triumph of the human immune system: A person appears to have subdued HIV without any medication at all. This person, dubbed an “elite controller,” appears to harbor no functional HIV virus. And there are signs this isn’t unique. A second elite controller studied had just one functional copy of the virus.
For those of us who have been on the infectious disease beat for years, this is a “wow” of a study. I was eager to find out more, so I called Tina Hesman Saey, the Science News writer who covered this report. “I knew that there were people who didn’t have detectable levels of virus in their blood,” Saey said. “But I didn’t know that they could do that without drugs.”
Saey, who has a Ph.D. in molecular biology and covers genetics, especially appreciates the clever way that the elite controllers’ immune systems defanged HIV: by sequestering the virus in a kind of genetic prison, the inactive parts of cellular DNA. “They were specifically embedded in the heterochromatin; it’s just locked up super tight so nothing in there gets out,” she said. Saey also appreciates the colossal amount of effort by the scientists to figure this out, examining more than 1.5 billion blood cells from the body of the first elite controller, and more than 1 billion from the second. “I was awed by the number of cells that they looked at.”
So decades after HIV first emerged as a killer, humankind is still making discoveries about how the body fights it. With the new coronavirus, we’re in the early stages of the learning process, even though it often feels like we’ve been waiting forever to figure out this particularly wily foe. Scientists have made progress with treatments, many groups are racing to test potential vaccines, and multiple countries have shown that even without a vaccine, it’s possible to contain the virus and return to a close-to-normal life. We’re not where we want to be, but we’re making progress.