Welcome to the Andrabi Lab

Raiees Andrabi

Raiees Andrabi is an Associate Professor of Medicine, Perelman School of Medicine, Division of Infectious Diseases, Department of Medicine, University of Pennsylvania. Raiees Andrabi earned his PhD degree from the All India Institute of Medical Sciences in Biochemistry and performed his postdoctoral work in Dennis Burton’s laboratory at The Scripps Research Institute. The overarching goal of the Andrabi laboratory is to design vaccine immunogens and strategies that elicit protective broadly neutralizing antibody (bnAb) responses against viruses with complex glycoprotein surfaces—and to translate these into effective human vaccines. The Andrabi Lab receives funding from the National Institutes of Health and The Gates Foundation.

Research Focus

The overarching goal of the Andrabi laboratory is to design vaccine immunogens and strategies that elicit protective broadly neutralizing antibody (bnAb) responses against viruses with complex glycoprotein surfaces—and to translate these into effective human vaccines. We focus on two main areas: 1) Structure-guided immunogen design—leveraging structure- and in vitro directed evolution guided strategies to develop vaccines targeting challenging viral surface antigens, including those from HIV, arenaviruses, and coronaviruses. 2) B cell immunobiology—deciphering the affinity maturation pathways required for bnAb development during infection and vaccination, with the aim of guiding next-generation vaccine design.

Our work has contributed important advances in vaccinology and antibody-mediated immunity. We developed germline-targeting trimer immunogens designed to initiate HIV V2-apex bnAb responses (Andrabi et al., Immunity, 2015) and an immunofocusing chimpanzee SIV Env trimer that showed promise in preclinical models (Andrabi et al., Cell Reports, 2019). More recently, we demonstrated that a single dose of the germline-targeting immunogen Q23-APEX-GT1 elicits cross-neutralizing antibodies in a stringent knock-in mouse model (Ghosh et al., Science Immunology, 2026). An improved immunogen, Q23-APEX-GT2, efficiently activated rare V2-apex–specific B cells in outbred rhesus macaques and elicited tier-2 cross-neutralizing mAbs, providing proof-of-principle that authentic bnAb precursors can be primed in an outbred primate model (Mishra et al., Immunity, 2026). Most recently, we showed that priming efficiency and early clonal dominance are key determinants of serum bnAb induction (Liang et al., bioRxiv, 2026). We have also defined mechanisms governing bnAb maturation and escape resistance during HIV infection (Lee & Andrabi et al., Immunity, 2017; Andrabi et al., Immunity, 2017).

Our coronavirus research has identified and advanced a conserved vulnerability with potential for pan-betacoronavirus vaccine development. We discovered the first human S2 stem-helix bnAbs against SARS-CoV-2 (Song et al., Nature Communications, 2021) and subsequently defined a conserved S2 stem-helix epitope shared across betacoronaviruses (Zhou et al., Science Translational Medicine, 2022). We demonstrated that antibodies targeting this site can protect against SARS-CoV-1, SARS-CoV-2, and MERS-CoV (Zhou et al., Immunity, 2023), and more recently established proof-of-principle that heterologous spike prime–boost vaccination can elicit S2 stem bnAbs in nonhuman primates that closely resemble human antibodies (Dueker et al., Cell Reports, 2026; Zhou et al., bioRxiv, 2026). In parallel, we have isolated potent sarbecovirus RBD bnAbs from humans and nonhuman primates (He et al., Nature Immunology, 2022; Science Translational Medicine, 2022; Song et al., Cell Reports, 2025), providing leads for antibody-based therapeutics and pan-sarbecovirus vaccine development.