PT  - JOURNAL ARTICLE
AU  - Huttner, Angela
AU  - Eperon, Gilles
AU  - Lascano, Agustina M.
AU  - Roth, Serge
AU  - Schwob, Jean-Marc
AU  - Siegrist, Claire-Anne
AU  - Lalive, Patrice H.
TI  - Risk of MS relapse after yellow fever vaccination
AID  - 10.1212/NXI.0000000000000726
DP  - 2020 Jul 01
TA  - Neurology - Neuroimmunology Neuroinflammation
PG  - e726
VI  - 7
IP  - 4
4099  - http://nn.neurology.org/content/7/4/e726.short
4100  - http://nn.neurology.org/content/7/4/e726.full
SO  - Neurol Neuroimmunol Neuroinflamm2020 Jul 01; 7
AB  - Objective To 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.Methods This 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.Results Of 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.Conclusions In 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 evidence This study provides Class IV evidence that for persons with MS, YFV may not increase relapse risk.ARR=annualized relapse rate; DMT=disease-modifying therapy; ERP=exposure-risk period; YF=yellow fever; YFV=yellow fever vaccine; PEP=pre-exposure risk period; PRP=postrisk period