An experimental nasal vaccine has demonstrated the ability to shrink cervical tumors in mice, offering a potential new therapeutic approach to fighting cancer caused by the human papillomavirus (HPV). The research, published November 12 in Science Translational Medicine, suggests that this vaccine could expand treatment options for patients already infected with HPV.
The Challenge of Existing Treatments
Currently, most HPV vaccines – like Gardasil-9 – are preventative, stopping the virus from infecting the body in the first place. Preventative vaccines have proven highly effective; a recent 2024 study in Scotland reported zero cases of cervical cancer among women vaccinated at age 12 or 13 since 2008. However, these vaccines do not work on existing infections. Patients who develop cervical cancer must rely on invasive treatments like surgery, radiation, and chemotherapy.
This leaves a gap in care for the estimated 660,000 new cervical cancer cases diagnosed each year globally, the vast majority of which are caused by HPV.
A Novel Therapeutic Approach
Researchers led by Rika Nakahashi-Ouchida at Chiba University in Japan are developing a therapeutic vaccine designed to trigger the immune system to attack existing tumors. While many labs are pursuing this approach, Nakahashi-Ouchida’s team took a novel route: a nanogel vaccine administered via nasal spray.
The vaccine delivers a modified, harmless protein from a cancer-causing HPV strain. In mice, this triggered an immune response, with cells migrating from the nasal mucosa to tumor tissue in the cervix, resulting in tumor shrinkage.
“I was very excited to see that,” Nakahashi-Ouchida says. “She hadn’t been sure that nasal vaccination could spark a response in tissue as distant as the cervix.”
The same effect was observed in preliminary experiments with macaques, where immune cells targeted cervical tissue after vaccination.
What’s Next?
While promising, the vaccine is still years away from clinical use. The team aims to broaden the vaccine’s effectiveness by incorporating proteins from multiple HPV strains. Nakahashi-Ouchida estimates that a viable nasal vaccine could be available within five years, pending further testing and refinement. This potential breakthrough could represent a significant advance in cervical cancer treatment, particularly for patients who cannot benefit from preventative vaccines.
