Inhibition of HIV-1 group M and O isolates by fusion inhibitors

We examined the susceptibility of HIV-1 group M and 0 isolates to the fusion inhibitors T-20 and T-1249. Unexpectedly, HIV-1 0 isolates were as sensitive as group M viruses to inhibition by T-20 but were usually less susceptible to T-1249. Our data suggest that T-20 has broad antiretroviral activity and would be effective in individuals with HIV-1 0 infection. However, polymorphisms in gp41 might affect the sensitivity of HIV-1 0 to second-generation fusion inhibitors.