A Yeast Infection Vaccine May Soon Become a Reality

Hold your horses, The Last of Us. Scientists have created an experimental vaccine that could be effective against multiple types of fungal germs, including those that cause vaginal yeast infections.

Researchers at the University of Georgia developed the vaccine candidate, code-named NXT-2. In their latest study with mice, NXT-2 appeared to protect the animals from a common culprit of yeast infection, Candida albicans. The team is now planning to forge ahead with human trials of the vaccine.

Compared to bacteria or viruses, fungi don’t make people sick as often. But there are some common fungal illnesses that cause plenty of misery, including yeast infections and ringworm. Fungi can also cause serious, life-threatening infections in people with weakened immune systems or otherwise poor health. And fungal infections in general are becoming more common, possibly due to factors like climate change (fungi usually prefer temperatures cooler than our bodies, but some species have likely already become more tolerant to us).

Another reason why fungi are becoming more dangerous is the lack of weapons available against them. We have far fewer antifungals than antibiotics, for instance, and no approved vaccines whatsoever. While new antifungals are needed, they’re ultimately a stopgap, since fungi can adapt and evolve resistance to them. So the UGA researchers are hoping that their “pan-fungal” vaccine can provide more of a long-term solution to the most worrying fungi out there.

In previous animal studies, the team’s NXT-2 vaccine appeared effective at preventing or reducing harm from three of the most common sources of invasive fungal infections in people (collectively representing 80% of fatal infections). This latest research, published this month in NPJ Vaccines, tested NXT-2 in a mouse model of vulvovaginal candidiasis.

NXT-2 provoked a strong immune response in the mice to C. albicans fungi, the researchers found, including in vaginal tissue. Vaccinated mice infected with the fungi also experienced reduced fungal burden and less vaginal tissue damage and inflammation.

“These studies provide supportive evidence of broad efficacy of NXT-2 and support the rationale for its further development as a single, pan-fungal vaccine for local and systemic fungal infections,” they wrote.

Though the vaccine may be able to tackle the most serious fungal infections, the researchers plan to first test it out in humans as a vaccine against recurrent vulvovaginal candidiasis (RVVC). These infections affect over 100 million women worldwide every year and can be incredibly stressful, the researchers note. Young and otherwise healthy women also tend to experience these infections more often, which should make recruiting potential volunteers for trials easier.

“RVVC is not life-threatening, but it is miserable. As many as one in 10 women develop the condition during their lifetime, suffering three or more yeast infections per year,” said lead author Karen Norris, a professor of immunology and translational biomedicine in the UGA College of Veterinary Medicine, in a statement from the university. “This is a huge need.”

Norris is also the CEO and founder of NXT Biologics, the biotech company developing NXT-2 commercially. And should NXT-2 succeed as hoped against yeast infections, the next step will be targeting the most dangerous fungi in the world.

“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.