Development of a cocktail of recombinant-expressed human rabies virus-neutralizing monoclonal antibodies for postexposure prophylaxis of rabies

To provide a cost-effective and safe replacement for human rabies immunoglobulin (HRIG), we used DNA recombinant technology to express 3 human rabies virus-neutralizing human monoclonal antibodies (huMAbs) in a rhabdovirus vector (RhV). Infection of either baby hamster kidney cells or CHO cells, with the resulting RhV-huMAb recombinant viruses, yielded high-level production (less than or equal to40 mug/mL/48 h) of RhV recombinant-expressed huMAbs (rhuMAbs) that differ in both isotype and epitope-recognition specificity. A cocktail of these rhuMAbs neutralizes several fixed and street wildtype rabies viruses (RVs). Mice and hamsters treated only once with this rhuMAb cocktail after infection with a lethal dose of RV were protected. In the mouse models, the post-exposure prophylaxis (PEP) efficacy obtained with the rhuMAb cocktail was comparable to that obtained with HRIG, a finding strongly suggesting that rhuMAbs should be given serious consideration for use in future PEP of humans.