Susan Zolla-Pazner is an American research scientist who is a Professor of Medicine in the Division of Infectious Diseases and the Department of Microbiology at Mount Sinai School of Medicine and a guest investigator in the Laboratory of Molecular Immunology at The Rockefeller University, both in New York City. Zolla-Pazner's work has focused on how the immune system responds to the human immunodeficiency virus (HIV) and, in particular, how antibodies against the viral envelope develop in the course of infection. In 1981, Zolla-Pazner and other researchers initially described the immunologic abnormalities afflicting homosexual men in New York City who were dying from an unknown sickness. In the years since, she has examined the body's immune response to the virus. She is the co-inventor on 23 patents and the author of more than 325 scientific publications. Research Zolla-Pazner’s work helped establish the central role of antibodies in protection from HIV infection. She proposed quantifying the antibodies directed at the second and third variable loops (V2 and V3) of the HIV envelope protein gp120, as observed in the Phase 3 RV144 clinical HIV vaccine trial, which involved 16,402 participants in Thailand. Her research indicated that high levels of antibodies to the second variable region of the virus envelope protein, V2, correlated with a reduced rate of infection. Antibodies to V3 were subsequently identified as an additional correlate of protection, exerting immune pressure on viruses infecting individuals who had received the vaccine. Zolla-Pazner's research indicated that the search for an effective vaccine should focus not only on inducing specific types of antibodies but on eliciting a durable antibody response, as post-hoc analysis showed the levels of antibodies waned within 6 months of the last dose of the vaccine. Her findings established the key role of antibodies specific for the virus envelope's variable regions in protection from HIV infection; they also validated her hypothesis that antibodies to variable regions could be protective—a highly controversial point until then. In the early days of the AIDS epidemic, the Zolla-Pazner lab described the hyperactivation of B lymphocytes in the blood of HIV-infected individuals. This discovery led her to develop methods to generate anti-HIV human monoclonal antibodies (mAbs) from the blood cells of HIV-infected individuals. Her lab isolated and described human mAbs capable of neutralizing the infectivity of the virus, and, later, isolated a mAb with strong neutralizing potency targeting a complex conformational region on the surface of