COVID-19 severity and mortality in multiple sclerosis are not associated with immunotherapy: Insights from a nation-wide Austrian registry. oleh Gabriel Bsteh, Hamid Assar, Harald Hegen, Bettina Heschl, Fritz Leutmezer, Franziska Di Pauli, Christiane Gradl, Gerhard Traxler, Gudrun Zulehner, Paulus Rommer, Peter Wipfler, Michael Guger, Christian Enzinger, Thomas Berger, AUT-MuSC investigators