Risk of MS relapse after yellow fever vaccination

Abstract

ObjectiveTo determine whether live-attenuated yellow fever vaccine (YFV) was associated with MS relapse, we evaluated the clinical courses of 23 patients in the year before and the year after immunization at the university hospital of Geneva, Switzerland.MethodsThis self-controlled retrospective cohort included adult patients with MS receiving YFV between 2014 and 2018 and defined the year before vaccination, the 3 months thereafter, and the 9 months following as the pre-exposure (PEP), exposure-risk (ERP), and postrisk (PRP) periods, respectively. The primary outcome was the relative incidence of relapse in the ERP vs the PEP. Secondary end points included the presence of new T2-weighted (T2) or T1-weighted gadolinium-positive (T1Gd+) MRI lesions.ResultsOf 23 patients with MS receiving YFV (20 relapsing MS and 3 primary progressive MS), 17 (74%) were women; mean age was 34 years (SD ±10); and 10 of 23 (40%) were treated with disease-modifying therapies (DMTs). Although 9 patients experienced 12 relapses in the PEP, only one experienced a relapse in the ERP; 3 other patients experienced one relapse each in the PRP. None of the 8 patients receiving natalizumab at the time of vaccination experienced relapse thereafter. In the PEP, ERP, and PRP, 18, 2, and 9 patients had new brain and/or spinal cord lesions on T2 or T1Gd + MRI, respectively.ConclusionsIn this cohort, YF vaccination was associated with neither an increase in MS relapse nor emergence of brain and/or spinal lesions. Further studies are warranted to confirm these findings.Classification of evidenceThis study provides Class IV evidence that for persons with MS, YFV may not increase relapse risk.

Protecting people with multiple sclerosis through vaccination

“…19 More recently, a small retrospective study reported that yellow fever vaccination was associated with neither an increase in MS relapses nor emergence of brain and/or spinal cord lesions. 20 These contrasting results could relate to differences in the efficacy profile of disease-modifying therapies used soon after yellow fever vaccination and we need further research to establish or exclude any potential causal association. 20…”

“…20 These contrasting results could relate to differences in the efficacy profile of disease-modifying therapies used soon after yellow fever vaccination and we need further research to establish or exclude any potential causal association. 20…”

Vaccinations in patients with multiple sclerosis: review and recommendations

“…Patients with MS planning travel to yellow fever endemic regions should be encouraged to think carefully about their itinerary. A small study of patients not on highly effective DMTs observed a significant increase in relapse rate following exposure to the yellow fever vaccine, 11 although this was not corroborated in a recent case series 32 . When yellow fever vaccination is essential, DMT cessation with a washout period is required.…”

Current Immunological and Clinical Perspective on Vaccinations in Multiple Sclerosis Patients: Are They Safe after All?

“…In comparison, another small study done in 2014–2018 on MS patients in Switzerland showed no association with MS relapses (4 out of 23 patients developed relapses) following YF vaccinations. In addition, as previously discussed, although taking natalizumab and co-administering live-attenuated vaccines is not recommended, none of the patients experienced relapses after YFV or a YFV-related adverse event [ 134 ].…”