Antiviral Prophylaxis for Herpes Simplex Virus Exposure in Immunocompromised Patients

Risk Stratification and Prophylaxis Indications

The National Comprehensive Cancer Network recommends antiviral prophylaxis for HSV-seropositive patients undergoing acute leukemia treatment, with a 60-80% reactivation risk without prophylaxis 1, 2
The National Comprehensive Cancer Network suggests antiviral prophylaxis for allogeneic HCT recipients during neutropenia and potentially longer depending on the degree of immunosuppression 1, 2
The National Comprehensive Cancer Network recommends antiviral prophylaxis for alemtuzumab-treated patients until at least 2 months after completion of therapy and until CD4 counts ≥200 cells/mcL 1, 2
The National Comprehensive Cancer Network suggests considering antiviral prophylaxis for patients with hematologic malignancies experiencing prolonged neutropenia 1, 2
The National Comprehensive Cancer Network recommends antiviral prophylaxis for any patient with prior HSV reactivation requiring treatment during all future episodes of neutropenia induced by cytotoxic therapy 1, 2

The National Comprehensive Cancer Network recommends choosing one of the following first-line agents: acyclovir 400 mg orally twice daily, valacyclovir 500 mg orally once or twice daily, or famciclovir at appropriate prophylactic doses 1, 2
The National Comprehensive Cancer Network notes that if receiving ganciclovir or foscarnet for CMV prophylaxis, additional acyclovir is not necessary as these agents are active against HSV 1, 2
The National Comprehensive Cancer Network recommends adding acyclovir, valacyclovir, or famciclovir if receiving letermovir for CMV prophylaxis, as letermovir lacks activity against HSV 1, 2

The National Comprehensive Cancer Network recommends prophylaxis throughout the entire neutropenic period during induction and consolidation chemotherapy for acute leukemia patients 1, 2
The National Comprehensive Cancer Network suggests extending prophylaxis for allogeneic HCT recipients with ongoing GVHD or continued systemic immunosuppression 1, 2
The National Comprehensive Cancer Network recommends prophylaxis for a minimum of 2 months post-alemtuzumab therapy and until CD4 ≥200 cells/mcL 1, 2

The National Comprehensive Cancer Network recommends foscarnet 40 mg/kg IV every 8 hours as the treatment of choice for documented or suspected acyclovir resistance 1, 2

The National Comprehensive Cancer Network advises against relying on clinical diagnosis alone in immunocompromised patients with atypical presentations and recommends obtaining laboratory confirmation 3
The National Comprehensive Cancer Network warns against assuming CMV prophylaxis covers HSV if the patient is receiving letermovir—separate HSV prophylaxis is required 1, 2
The National Comprehensive Cancer Network recommends against discontinuing prophylaxis prematurely in allogeneic HCT recipients who develop GVHD or require ongoing immunosuppression 1, 2
The National Comprehensive Cancer Network advises against using topical antivirals as they are substantially less effective than systemic therapy 1, 3