Neutralizing Antibodies Protect against Oral Transmission of Lymphocryptovirus

Epstein-Barr virus (EBV) is a cancer-associated pathogen for which there is no vaccine. Successful anti-viral vaccines elicit antibodies that neutralize infectivity; however, it is unknown whether neutralizing antibodies prevent EBV acquisition. Here we assessed whether passively delivered AMMO1, a monoclonal antibody that neutralizes EBV in a cell-type-independent manner, could protect against experimental EBV challenge in two animal infection models. When present prior to a high-dose intravenous EBV challenge, AMMO1 prevented viremia and reduced viral loads to nearly undetectable levels in humanized mice. AMMO1 conferred sterilizing immunity to three of four macaques challenged orally with rhesus lymphocryptovirus, the EBV ortholog that infects rhesus macaques. The infected macaque had lower plasma neutralizing activity than the protected animals. These results indicate that a vaccine capable of eliciting adequate titers of neutralizing antibodies targeting the AMMO1 epitope may protect against EBV acquisition and are therefore highly relevant to the design of an effective EBV vaccine. [Display omitted] An anti-EBV mAb, AMMO1, limits viral replication following challenge in humanized miceAMMO1 cross-reacts with and neutralizes rhesus lymphocryptovirusAdequate levels of AMMO1 prevent oral acquisition of rhLCV in macaquesProtection afforded by neutralizing antibody provides proof of concept for EBV vaccines Epstein-Barr virus is a cancer-associated lymphocryptovirus for which there is no vaccine. Singh et al. demonstrate that passive delivery of a potent neutralizing antibody protects against lymphocryptovirus challenge in two animal models. These results indicate that neutralizing antibodies may be an important component of an effective EBV vaccine.