Rabies vaccination and multiple sclerosis relapse: A retrospective cohort study

BackgroundNo studies assessing rabies vaccine (RV) tolerability in persons with multiple sclerosis (MS) have been conducted. Given the lack of safety data, RV is recommended essentially only for post-exposure prophylaxis, which difficult to administer effectively many rabies-endemic countries. We sought determine whether administration as pre-exposure prophylaxis was associated MS relapse.MethodsThis retrospective cohort study compared clinical courses patients year before and after vaccination. The vaccination defined risk period, three months thereafter exposure-risk following nine post-risk period. All adult immunized between 2014 2018 available medical records two-year window were included. primary outcome incidence symptomatic relapse period versus period.ResultsFifty-five received at least one dose RV. Most (38/55, 69%) female; mean age 38.5 years (SD ±9.2). While 21 (38%) experienced 24 relapses vaccination, (5%) each post-vaccination period; others a total four subsequent annualized rates pre-exposure, exposure-risk, periods 0.44, 0.22, 0.10, respectively (rate ratio periods, 0.509 [95% CI 0.098–1.677]).ConclusionsIn this cohort, not relapse. Larger, prospective are needed confirm these results.