The lyssavirus genus is a diverse group of viruses all capable of causing an invariably fatal disease known as rabies, most commonly caused by the prototype species rabies virus (RABV). Alongside RABV the lyssavirus genus currently contains 17 other viruses capable of causing rabies. These viruses are broadly categorised into phylogroups according to the predicted level of vaccine protection, with protection from current vaccines and therapeutics afforded against phylogroup I but not II or III. Current evidence suggests that for a protective neutralising antibody response against RABV a neutralising antibody titre of 0.5 IU/ml is sufficient. Studies using cross protection assays, have suggested that for protection against more divergent members of the genus, even those in phylogroup I, 10-fold or greater than the 0.5 IU/ml antibody titres are required. The continued discovery of novel lyssaviruses globally warrants an in-depth assessment of the protective titre required to protect against all the lyssaviruses to inform occupationally high-risk groups (e.g., scientists, bat workers and speleologists). This study suggests that a minimum titre of 5 IU/ml is required for the neutralisation of all phylogroup I lyssaviruses in vitro. Whilst, results from live virus neutralisation assays and antigenic cartography techniques suggest that a minimum of 5 distinct lyssavirus glycoprotein antigens would have to be included in any pan-lyssavirus vaccine. Certainly, representative antigens from all lyssavirus species characterised in phylogroups II and III are required to stimulate a pan-lyssavirus response.