Luna G, Alping P, Burman J et al.  Infection risks among patients with multiple sclerosis  treated with fingolimod, natalizumab, rituximabm  and injectable therapies.  JAMA Neurology2020; 77:184-91.

Swedish study examines risk of infections severe enough to cause hospitalization in 6421 MS patients and controls.  The rate of infections among patients taking injectibles was higher than the population 8.9 v 5.2 per 1000 person years. It was higher still in patients taking fingoli,od (14.3), and natalizumab (11.4) and highest among patients taking rituximab (19.7).