Rabies vaccination and multiple sclerosis relapse: A retrospective cohort study

Area of Science:

• Neurology
• Immunology
• Vaccinology

Background:

• Limited data exists on rabies vaccine (RV) tolerability in multiple sclerosis (MS) patients.
• Current recommendations restrict RV use in MS to post-exposure prophylaxis due to safety concerns.
• This study addresses the need for safety data regarding pre-exposure RV in MS.

Purpose of the Study:

• To evaluate the association between rabies vaccination and the risk of multiple sclerosis relapse.
• To determine if pre-exposure rabies vaccination impacts the clinical course of MS.

Main Methods:

• Retrospective cohort study of adult MS patients who received RV between 2014-2018.
• Comparison of MS relapse incidence in the year before vaccination versus the post-vaccination exposure-risk period (3 months).
• Analysis included annualized relapse rates and rate ratios.

Main Results:

• Fifty-five MS patients received RV; 69% were female, mean age 38.5 years.
• Relapses decreased significantly post-vaccination: 24 relapses pre-vaccination vs. 1 relapse in the exposure-risk period.
• Annualized relapse rates were 0.44 (pre-exposure) vs. 0.22 (exposure-risk), indicating a potential reduction.

Conclusions:

• Rabies vaccination was not associated with an increased risk of clinical MS relapse in this cohort.
• Findings suggest rabies vaccination may be safe for pre-exposure prophylaxis in MS patients.
• Larger, prospective studies are recommended to validate these safety findings.