mRNA-1608: An Investigational Therapeutic Vaccine Candidate for Herpes Simplex Virus Type 2

1. Executive Summary

mRNA-1608 is an investigational therapeutic messenger RNA (mRNA) vaccine candidate currently under development by Moderna, Inc..[1] This vaccine is primarily engineered to target Herpes Simplex Virus type 2 (HSV-2), the principal etiological agent responsible for genital herpes, while also holding the potential for cross-protective immunity against Herpes Simplex Virus type 1 (HSV-1).[1] The fundamental therapeutic objective of mRNA-1608 is to alleviate the clinical burden associated with recurrent HSV-2 infections. This is anticipated to be achieved through the induction of a robust and multifaceted immune response, encompassing the generation of neutralizing and effector antibodies, complemented by the stimulation of potent cell-mediated immunity.[1]

Currently, mRNA-1608 is being evaluated in a fully enrolled Phase 1/2 clinical trial (NCT06033261, also identified as mRNA-1608-P101). This study is specifically designed to assess the vaccine's safety, immunogenicity, and preliminary clinical benefit in adult participants with a documented history of recurrent genital herpes.[1] The development of an effective therapeutic vaccine for HSV represents a significant unmet medical need, given the high global prevalence of genital herpes, the chronic nature of the infection characterized by recurrent painful lesions, and the limitations of existing antiviral therapies which only manage symptoms rather than prevent recurrences or eradicate the virus.[2]