Are all subtypes created equal? The effectiveness of antiretroviral therapy against non-subtype B HIV-1.

Received 9 February 2009; accepted 11 February 2009; electronically published 30 March 2009. Reprints or correspondence: Dr. Davey M. Smith, University of California–San Diego, 9500 Gilman Dr., MC 0679, La Jolla, CA 92093 ([email protected]). Clinical Infectious Diseases 2009; 48:1306–9 2009 by the Infectious Diseases Society of America. All rights reserved. 1058-4838/2009/4809-0025$15.00 DOI: 10.1086/598503 Currently, 24 active antiretroviral agents are available for use in the United States. These agents target and interrupt an array of HIV functions, including reverse transcription, proteolysis, envelope fusion, and integration [1]. When used in a variety of combinations, these agents have greatly reduced the morbidity and mortality associated with natural HIV infection in the United States [2]. In this issue of Clinical Infectious Diseases, Geretti et al. [3] demonstrate in an observational study that modern combination antiretroviral therapy works, even when the infecting virus is non–subtype B HIV-1. Specifically, this study examined the rates of viral suppression with antiretroviral therapy during infection with subtypes A, C, and D and with the circulating recombinant form (CRF) 02_AG. This is important, because modern antiretroviral therapy was developed on the basis of investigations of subtype B HIV-1 infection, even though this subtype accounts for only 12% of worldwide infections and is almost nonexistent in many regions [4].