 Based on 1:1 randomization, an anticipated relative reduction of the risk of progression of 50 from 50 in the control arm to 25 in Mg recipients, information from our case series plus indirect evidence from studies on severe tetanus, 90 power and a two-sided 5 significance level, 85 patients per treatment group are required. To allow for some violations of our assumptions and losses to follow-up, we plan to recruit 190 patients 95 patients per treatment arm into the study. 