Epstein-Barr Virus Vaccine

As of 2026, no vaccine against Epstein-Barr virus was yet available, though the virus establishes lifelong latent infection, causes infectious mononucleosis, and there is increasing evidence that it may be a trigger of multiple sclerosis. Epstein-Barr virus is a dual-tropic virus that infects both B cells and epithelial cells, and because it expresses very different proteins during its lytic and latent phases, antiviral agents that work by inhibiting viral DNA replication have shown little effectiveness against it, are expensive, and carry a risk of resistance and side effects. Several clinical trials for a vaccine were conducted between 2006 and 2008, targeting the viral protein Gp350/220, though this would only block infection of B cells rather than epithelial cells; a candidate called MVA-EL has also been proposed as a target for Epstein-Barr virus-positive cancers. In April 2018 the first human antibody shown to block the virus, called AMMO1, was discovered, neutralizing infection of both cell types, and in 2021 Moderna announced two mRNA vaccine candidates, a prophylactic mRNA-1189 and a therapeutic mRNA-1195, the first of which began Phase I clinical trials in January 2022.