Two-Step Vaccine Strategy Eliminates Herpes Infection in Preclinical Trials
Yale School of Medicine researchers report a two-part vaccination strategy against genital herpes that prevented infection in preclinical mouse models. The study was published June 19 in Science Immunology.
Vaccine Strategy: "Prime and Pull"
The approach combines an intramuscular injection (prime) with localized application of nanoparticles called BEACON to the vaginal tissue (pull). The injection primes the immune system, while the nanoparticles recruit immune cells to the site of infection.
- Prime: Standard intramuscular injection with herpes antigen.
- Pull: Intravaginal application of BEACON nanoparticles (chemokine linked to immunostimulatory DNA) plus virus antigen.
Key Findings
Protection: 80% of vaccinated mice showed no signs of disease for at least six months after herpes virus exposure, compared to 40% with intramuscular injection alone.
- Local Immunity: BEACON established strong, long-lasting B cell and antibody responses in vaginal tissue.
- Safety: The nanoparticle formulation required lower doses of immunostimulatory DNA, preventing inflammation seen in earlier experiments.
Limitations and Next Steps
The approach is currently tested only in female mice. Researchers are collaborating with Stanford University to develop a human-compatible formulation (e.g., vaginal suppository). They also plan to explore a nasal delivery method for potential use in men. Human clinical trials are needed before any vaccine becomes available.
Attribution
- Senior author: Akiko Iwasaki, Sterling Professor of Immunobiology, Yale School of Medicine.
- Lead author: Sachin Bhagchandani, postdoctoral fellow in Iwasaki's lab.
The researchers note that genital herpes has no cure and current treatments only manage symptoms. The study was funded by the National Institutes of Health and the Howard Hughes Medical Institute.