A missed point in deciphering the viral synergy between herpes simplex virus and HIV

Philippe Van de Perre and colleagues 1 argue that herpes simplex virus (HSV) 2 and HIV infections are synergistic, since suppression of HSV2 decreases HIV load, while Rex G Cheng and Douglas F Nixon 2 insist that interactions between HSV2 and HIV-1 are more complex and that HSV2 coinfection might, in certain cases, be associated with elevated CD4+ T-cell counts. 3 Both groups provide arguments on the basis of their own work and selected results of various clinical trials. 4‐7 Although there has been some criticism of the design and interpretation of results of some of these trials, 8‐10 all of them have one thing in common: they use aciclovir or its prodrug valaciclovir to suppress HSV2 replication and to investigate whether such suppression affects HIV replication and infection.