Currently, there are no treatments or vaccines against Epstein-Barr virus (EBV) infection. Here, Zhu et al. isolate gH/gL-specific antibodies from infected donors and identify 1D8, that substantially reduces infection levels in both, B- and epithelial cells, and reduces tumor burdens in EBV-challanged humanized mice due to interferance with the gH/gL-mediated membrane fusion and binding.