Praxis Medical Insights

Est. 2024 • Clinical Guidelines Distilled

Made possible by volunteer editors from the University of Calgary & University of Alberta

Last Updated: 8/24/2025

HSV Prophylaxis Recommendations

High-Risk Populations Requiring HSV Prophylaxis

  • The National Comprehensive Cancer Network recommends that HSV-seropositive patients with acute leukemia undergoing induction or reinduction chemotherapy should receive prophylaxis during periods of neutropenia 1, 2
  • The National Comprehensive Cancer Network suggests that hematopoietic cell transplant (HCT) recipients who are HSV-seropositive should receive prophylaxis during neutropenia and possibly longer depending on immunosuppression level 1, 3
  • Allogeneic HCT recipients with graft-versus-host disease (GVHD) require extended prophylaxis, as recommended by the National Comprehensive Cancer Network 1
  • Autologous HCT recipients should receive prophylaxis during neutropenia, according to the National Comprehensive Cancer Network 4
  • Patients with chronic lymphocytic leukemia treated with alemtuzumab should receive prophylaxis until at least 2 months after completion of therapy and until CD4+ counts reach ≥200 cells/mcL, as recommended by the National Comprehensive Cancer Network 1, 5
  • The National Comprehensive Cancer Network recommends that patients with intermediate risk for HSV reactivation, including those with hematologic malignancies with prolonged neutropenia, should receive prophylaxis 4
  • Patients with prior HSV reactivation requiring treatment should receive prophylaxis during all future episodes of neutropenia induced by cytotoxic therapy, as suggested by the National Comprehensive Cancer Network 4
  • HSV-seropositive children undergoing cancer treatment should receive prophylaxis, according to the National Comprehensive Cancer Network 4
  • The National Comprehensive Cancer Network recommends acyclovir, valacyclovir, or famciclovir as first-line agents for HSV prophylaxis 1, 3
  • For acyclovir-resistant HSV infection, foscarnet is the agent of choice, as recommended by the National Comprehensive Cancer Network 1
  • Patients receiving ganciclovir or foscarnet for CMV prophylaxis do not need additional HSV prophylaxis, according to the National Comprehensive Cancer Network 1
  • Patients receiving letermovir for CMV prophylaxis require additional HSV prophylaxis, as suggested by the National Comprehensive Cancer Network 1

Duration of Prophylaxis

  • Acute leukemia patients should receive prophylaxis during the period of neutropenia, as recommended by the National Comprehensive Cancer Network 1
  • Allogeneic HCT recipients should receive prophylaxis during neutropenia and possibly longer, with extended prophylaxis for those with GVHD or frequent pre-transplant HSV reactivations, according to the National Comprehensive Cancer Network 1
  • Autologous HCT recipients should receive prophylaxis during neutropenia, as suggested by the National Comprehensive Cancer Network 4
  • Alemtuzumab-treated patients should receive prophylaxis until at least 2 months after completion of therapy and until CD4+ counts reach ≥200 cells/mcL, as recommended by the National Comprehensive Cancer Network 1, 5

Clinical Importance of HSV Prophylaxis

  • Without prophylaxis, HSV reactivation occurs in 60-80% of seropositive HCT recipients and acute leukemia patients undergoing induction/reinduction therapy, according to the National Comprehensive Cancer Network 1, 2
  • HSV reactivation can cause significant mucosal damage, resulting in increased pain, limited ability to maintain oral hydration and nutrition, and increased risk of bacterial and fungal superinfections, as reported by the National Comprehensive Cancer Network 1, 3

Special Populations

  • HIV-infected individuals with frequent or severe HSV recurrences should receive daily suppressive therapy with acyclovir, famciclovir, or valacyclovir, as recommended by the Centers for Disease Control and Prevention 6, 8
  • Pregnant women with frequent, severe recurrences of genital HSV may require antiviral prophylaxis, according to the Centers for Disease Control and Prevention 6, 8
  • Pediatric patients, specifically HSV-seropositive children undergoing cancer treatment, should receive HSV prophylaxis, with dosing adjusted based on age and weight, as suggested by the National Comprehensive Cancer Network 4

REFERENCES

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