 This study found that two commercially available rabies immunoglobulin, RIG, products did not effectively neutralize many listoviruses, including those outside of phylogroupi. However, higher dosages of these RIG products may be necessary to neutralize some listoviruses. Alternatives to RIG are needed to provide effective protection against listoviruses. This article was authored by Jessica Courts, Natalie Vilgevan, Jacqueline Weyer, and others.