University of Georgia researchers have developed a groundbreaking vaccine that could become the first to prevent pathogenic fungal infections, addressing what the World Health Organization considers one of the top threats to public health. The vaccine, designated NXT-2, has successfully demonstrated protection against the three most common fungal pathogens responsible for more than 80% of fatal fungal infections.
The latest study, published in Nature's NPJ Vaccines, showed that the vaccine successfully protects against and treats vaginal yeast infections in mice. This finding builds on previous research demonstrating the vaccine's efficacy in four preclinical animal models, including nonhuman primates, and clears the path for clinical trials to begin.
Addressing Growing Antifungal Resistance
"The thing that's keeping researchers like me up at night is increasing antifungal drug resistance," said Karen Norris, lead author of the study and professor of immunology and translational biomedicine in the UGA College of Veterinary Medicine. Norris, who is also CEO and founder of NXT Biologics, the company behind the vaccine, emphasized the urgency of the problem: "It's not a prediction. We're living it right now."
The vaccine aims to prevent fungal infections before they occur, potentially reducing reliance on antifungal medications. "We can't just keep swinging away and trying to make new drugs to fight fungal infections because we're going to lose," Norris explained. "These organisms are always adapting to resist new drugs."
Clinical Trial Strategy
The first clinical trials will target women with recurrent vulvovaginal candidiasis (RVVC), a condition caused by candida fungus that affects hundreds of millions of women globally. The condition costs billions of dollars in healthcare visits, medication, and lost productivity each year in the United States alone.
"RVVC is not life-threatening, but it is miserable," Norris noted. As many as one in 10 women develop the condition during their lifetime, suffering three or more yeast infections per year. Current treatment protocols rely on one class of drug, increasing the likelihood of resistance development, and these medications cannot be used during pregnancy and don't prevent future infections.
The choice to begin trials with RVVC patients is strategic. Most women suffering from recurrent yeast infections are young and otherwise healthy, making them an ideal population for Phase 1 clinical trials. The results will inform future trials in more vulnerable patient populations.
Expanding to High-Risk Populations
Following the initial trials, researchers plan to test the vaccine in transplant recipients and cancer patients, two groups particularly vulnerable to life-threatening fungal infections. "I've had a physician say to me, 'I have patients that I get through stem cell transplants for their cancer treatment, and then they get aspergillosis. I often don't have adequate treatment for that,'" Norris reported. Pulmonary aspergillosis is a serious complication of stem cell transplant treatment, with up to half of affected patients dying from the infection.
"That's where I believe this vaccine will do the most good: in people who are at high risk for highly dangerous, life-threatening infections," Norris said.
Growing Threat Population
Fungal infections are most commonly seen in people with immune disorders, including those with uncontrolled HIV or impaired immunity from therapies like chemotherapy or anti-inflammatories. However, previous research from Norris and colleagues showed that the at-risk population has expanded in recent years.
Their study demonstrated that people with diabetes, chronic obstructive pulmonary disease (COPD), or co-infections such as COVID-19, tuberculosis, or flu are likewise at higher risk of developing fungal infections. As drug resistance grows and infections become more difficult to treat, prevention becomes increasingly critical.
Scientific Breakthrough
This represents the first fungal vaccine to demonstrate broad, cross-protective antifungal immunity in multiple animal models, which researchers say bodes well for future clinical trials. The study was co-authored by researchers from the UGA Center for Vaccines and Immunology, including Daniel Wychrij, Taylor Chapman, Whitney Rabacal, Hubertine Willems, and Kwadwo Oworae, along with Emily Rayens from UGA's Department of Infectious Diseases and Brian Peters from the University of Tennessee.
