Who is Donor 45? He's a 65-year-old gay, African-American man who has been living with HIV (but healthy) for 20 years. More importantly, he's part of a small group of people who are infected with HIV, but whose bodies have managed to naturally stave off symptoms of the illness. In some cases, these people, called long-term non-progressors, even end up with virus levels so low as to be nearly undetectable.
Fascinatingly, Donor 45 is NOT one of those patients. His viral load is similar to that of people who get sick. That's because his immune system doesn't destroy HIV. Instead, it produces antibodies that prevent HIV from invading his cells.
All people infected with HIV produce antibodies in response to the infection. What's different is that Donor 45's antibodies actually work. For reasons that aren't clearly understood, most antibodies against HIV either aren't effective at all, or are only effective against certain strains—not terribly useful with a virus that mutates as frequently as HIV does. Donor 45's are capable of controlling as much as 91% of HIV strains. So he stays healthy, even while the virus continues to live in his body. People like Donor 46 can still infect others, but they, themselves, might live entirely normal lifespans without significant illness.
Some good links to read more about non-progressors:
- New York Times: AIDS and the secret of long-term survivors
- PBS Frontline: How HIV works and why some people are "immune"
- The Body: Compilation of several personal stories from long-term non-progressors as well as science and analysis about why some people survive
- Two studies recruiting long-term non-progressors for further research