Alison Rodger, MD, is one of the most consequential HIV scientists in the history of the disease. Her research, much of it done at University College London, demonstrated definitively that a person with an undetectable viral load does not transmit HIV via sex.


Anecdotal evidence from serodiscordant couples had already suggested that people with undetectable viral loads don’t transmit HIV. Rodger and her colleagues proved that Undetectable Equals Untransmittable (U=U) via rigorous adherence to the scientific method. By proving that U=U, she helped to usher in a new era in the battle against the virus.


“We’ve been building the evidence for about two decades, and we know that a person’s viral load is the biggest determinant of risk,” says the Scottish-born Rodger. “But the PARTNER studies that I did were kind of the tipping point in our approach to messaging. Those studies gave people the confidence to be definitive about U=U. Actually, the risk is zero.”


Rodger’s collaboration with U=U evangelist Bruce Richman, founding executive director of the Prevention Access Campaign, has been especially fruitful.


“Alison’s revolutionary research provided overwhelming evidence for the U=U movement,” Richman says. “She didn’t stop at research. She’s worked tirelessly to ensure the science reaches the field, enabling millions of people living with HIV to live and love without fear. It’s been one of my life’s greatest joys to work with Alison to translate her research into real-world impact.”


In addition to saving lives and combating stigma, the science behind U=U is helping to roll back laws from the 1980s and ’90s that made it a crime not to disclose your HIV status to sexual partners, regardless of whether HIV was transmitted. A punitive response to a heavily stigmatized disease, these laws criminalized the sex lives of people with HIV. And by amplifying the stigma and discouraging testing and treatment, these reactionary laws made the AIDS crisis even more lethal.


Currently, Rodger’s research is helping activists around the world to repeal those laws.


“The PARTNER data challenges these laws because there is no risk,” she says. “And there’s been a lot of repeal of these laws because of U=U. I think one of the strengths of U=U is actually the evidence behind it. It’s not simply an activist or community rallying cry. It’s based on such robust evidence, and I think that’s what convinces you.”


If Rodger remains modest about the scientific and political impact of her work, it’s because to her, the real heroes in her remarkable journey are the people who volunteer for clinical trials and research studies. It’s their sacrifice that propels the science, a fact she’s keen to note whenever she presents her research. (Go here for the pros and cons of clinical trials.)


“My final slide [in presentations] is always a huge thanks to people who generously took part in these studies, people with HIV who so generously took part just to push the science a little bit further. They’re the real heroes of all these studies.”