Acyclovir Prophylaxis of Herpes-Simplex-Virus Infections: A Randomized, Double-Blind, Controlled Trial in Bone-Marrow-Transplant Recipients

We conducted a double-blind, placebo-controlled study of acyclovir prophylaxis against infection with herpes simplex virus (HSV) in 20 seropositive recipients of bone-marrow transplants. Acyclovir or placebo was administered for 18 days, starting three days before transplantation. Culture-positive HSV lesions developed during the study in seven of the 10 patients who received placebo. In contrast, no such lesions appeared in the 10 patients who received acyclovir (P≃0.003). None of the patients had evidence of drug toxicity. Five of the patients treated with acyclovir had mild culture-positive HSV infections after cessation of the drug, and two additional patients shed virus without having lesions. Acyclovir appears to be a potent inhibitor of HSV replication. Although acyclovir does not appear to eradicate latent infection, it can provide effective prophylaxis against reactivated infections. (N Engl J Med. 1981; 305:63–7.). HERPES-simplex-virus (HSV) infections are a major cause of morbidity after bone-marrow transplantation.^1,2 A retrospective review of the experience at Johns Hopkins indicated that 45 (42 per cent) of 107 marrow recipients had HSV infections. The median time of onset was eight days after transplantation. Pretransplantation complement-fixation titers of anti-HSV antibody were available in 93 of the 107 patients. Whereas active herpetic lesions appeared in only six of 42 patients (14 per cent) with a titer of less than 1:8, acute HSV infections developed in 37 of the 51 patients (73 per cent) with a titer of 1:8 or greater. Thus,. . .