To safeguard against the attack of disease, H. Ali (a.s.) has prescribed this Dua which is to be recited 3 times always.
BISMILLAHIR RAHMANIR RAHEEM
ALLAAHO QADEEMUN AZALIYYUN YOZEELUL ELAL, WA HOWA QAAA-EMUN AZALIYYUN BIL AZALIYYATE LAM YAZAL WALAA YOZAALO BE RAHMATEKA YAA ARHAMAR RAAHEMEENA WA SALLALLAAHO A'LAA MOHAMMADIWN WA AALEHIT TAYYEBEENAT TAAHEREENA.