# HSV-1 and HSV-2 Treatment Update 2026: What new discoveries are scientists making?
**Simple answer: A complete cure for HSV-1 and HSV-2 is not possible even in 2026.** Authoritative bodies like the World Health Organization and the NIH are clear—current antiviral drugs can only inhibit active replication of the virus, but cannot completely clear the latent virus in neurons. However, several important advances have been made this year: **Pritelivir (Hovilpri) has been approved by the FDA**, and new-generation drugs like **Adibelivir (IM-250)** are advancing in clinical trials.
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| HSV-1 and HSV-2 Cure Update 2026: What Scientists Are Discovering |
## Pritelivir approved: First drug with a new mechanism of action in 30 years
On October 9, 2026, the US FDA approved Pritelivir (Hovilpri) tablets for the treatment of adult patients with immunocompromised mucocutaneous HSV infections who are resistant to or have not received adequate response from conventional drugs (acyclovir, valacyclovir, famciclovir).
This drug belongs to the helicase-primase inhibitor (HPI) class, which works in a completely different way from conventional drugs. Conventional drugs require activation by the virus's thymidine kinase (TK), and mutations in TK are the main cause of drug resistance. Pritelivir acts directly on the virus's DNA replication mechanism, so it is also sensitive to TK-deficient, acyclovir-resistant virus strains. It is effective against both HSV-1 and HSV-2, and is taken orally once a day.
Key data from the PRIOH-1 Phase 3 clinical trial (approximately 100 immunocompromised patients):
| Evaluation Index | Pritelivir Group | Conventional Treatment Group |
| :--- | :--- | :--- |
| **Complete healing of all lesions by 28 days** | **63%** | 34% |
| **Complete healing of all lesions by 42 days** | **82%** | 42% |
| **Discontinuation due to side effects** | **2%** | 20% |
The healing rate in the Pritelivir group was approximately twice that of the conventional treatment group. The biggest clinical advantage is that it can be taken orally at home, avoiding the need for hospitalization and IV drips, which is very important for patients with already weakened immunity.
## Adibelivir (IM-250): Ability to Target Dormant Viruses
Adibelivir (IM-250) is another HPI drug that has shown impressive results on over 50 clinical isolates in research published in *Antiviral Research* in 2026. Its average EC50 (for HSV-1) is 21 nM and 35 nM (for HSV-2), while acyclovir's EC50 is 883 nM and 1456 nM, respectively, meaning Adibelivir's potency is approximately 40 times greater than that of acyclovir.
Most importantly, adebelivir is effective against acyclovir-resistant virus strains and exhibits synergistic effects when used in combination with acyclovir, penciclovir, and foscarnet. The drug completed its Phase 1 program in January 2026, and in June 2026, the first patient enrolled in a Phase 2a clinical trial evaluating its effectiveness in patients with recurrent genital herpes.
## Other Research Directions
Bispecific Antibody: Research published in *Frontiers in Immunology* (May 2026) developed a bispecific antibody that simultaneously targets both gB and gD. It blocks cell-to-cell transmission and entry of the virus more effectively than either antibody alone, and exhibits activity against both HSV-1 and HSV-2.
Zinc oxide-PVA nanocomposite: According to research published in *Microbial Pathogenesis* (February 2026), this nanocomposite reduced the viral load of acyclovir-sensitive HSV-1 by 99.5% and acyclovir-resistant HSV-1 by 98.3%, offering potential for future localized treatment.
Caesappanin C (CAP): According to research published in *Phytomedicine* (February 2026), this natural plant compound inhibits virus entry by binding to the gB protein, and also reduces the inflammatory response by interacting with HSP90β. In mice, it reduced lesions and improved survival rates.
Targeting viral recombination proteins: A review in the *Annual Review of Virology* (2026) reported that HSV replication depends on the UL12 exonuclease and the ICP8 annealing protein, which provide new targets for the development of broad-spectrum antiviral drugs.
## Vaccine Status: Still Challenging
Moderna's Phase 1/2 trial (NCT06033261) of mRNA-1608, a therapeutic vaccine, published results in May 2026, primarily evaluating safety and immune response. However, it has not yet been proven to effectively reduce disease incidence or transmission.
The NIH's 2026 review clearly stated that there have been no major advances in herpes treatment for more than 40 years, and an effective vaccine is still unavailable. For an effective vaccine, neutralizing antibodies alone are not sufficient; both multifunctional antibodies and tissue-resident T cell immunity are required.
## Conclusion
A complete cure for HSV-1 and HSV-2 is still not possible in 2026. PritiLivir's approval is primarily for immunocompromised patients who are resistant to conventional medications.