From the Research
Herpes Simplex Virus Vaccine Efficacy
- The current understanding of the immune responses involved in latency and reactivation of Herpes Simplex Virus (HSV) provides a unique challenge to the development of vaccines 1.
- There are no approved vaccines currently available for either prophylaxis or therapy of HSV infections 1, 2.
- Various promising candidates are in the pre-clinical and clinical phases of study, with a focus on preventative and therapeutic vaccines, some with a dual use as both immunotherapeutic and prophylactic 1.
Mechanism of HSV Infection and Vaccine Development
- HSV infections are prevalent worldwide, and a vaccine to prevent genital herpes would have a significant impact on this disease 3.
- The virus can potentially be controlled with vaccines since humans are the only known host, but despite the development and trial of many vaccines, this has not yet been possible due to the high latency potential of the virus 4.
- Novel approaches toward developing safe and effective live-attenuated vaccines have demonstrated high efficacy in various preclinical models of herpetic disease, with the ultimate goal of preventing or reducing primary infections or reducing the frequency and severity of disease associated with reactivation events 2.
Immune Response to HSV Infection
- Numerous immune cells, particularly natural killer cells and interferon gamma, and pathways that are used by the body to fight HSV infections have been identified 4.
- The virus has developed different mechanisms, including using different microRNAs to inhibit apoptosis and autophagy, to avoid clearance and aid latency induction 4.
- T cell immunity is the correlate of immunity for the only effective therapeutic herpesvirus vaccine, the zoster vaccine, and cellular immunity at the site of reactivation is likely critical for an effective therapeutic vaccine for certain viruses 5.