Dear scholar, As-Salmau `Alaykum wa Rahamtu Allah wa Barakatuh. Recently, some Muslim doctors reviewed the issue of immunization against a likely future attack of a specified disease(s) in a public lecture. They argue that it is unacceptable for a Muslim to immunize himself/herself against a disease that is believed will occur in future. This include immunization of babies against childhood diseases such as Polio, Measles, etc. They claim that doing so contravenes the principle of `Ilm-l-Ghayb (Knowledge of the Unseen). What are your comments on this?