Reference: Explanation of the Book of Eemaan: 18- 8-1430 H
Question: May Allaah reward you, a questioner is asking about the ruling of leaving off an act of worship that one regularly practices fearing swine flu, such as a person who regularly used to perform ‘Umrah during Ramadaan?
Response: There is no harm if you fear catching a contagious disease, the Prophet – صلى الله عليه و سلم – ordered people not to enter a land that has an epidemic, nor to exit from it [if one is in it]. So if a disease spreads in a certain country, one should not travel from that country so as not to spread that disease, nor should a person travel to the country that has that disease, acting upon taking the causes, and this is a form of protection.
So there is no harm in doing so, if it is established that there is a disease in the country during Hajj or ‘Umrah – if it is established that there is a contagious disease there, then do not travel. Delay your Hajj or ‘Umrah to a later time. So there is no problem in doing so, this is a way of protecting oneself, Yes.