Taking An Injection Or Vaccine While Fasting

It is permissible to take a flu vaccine or injection when one is fasting, because the medicine is delivered to the body through a porous medium (i.e. the skin) and not through the usual oral passage or route. This medium is not contrary to the mediums that nullify the fast for substances to enter the body. Similarly, as the application of oils on the body does not invalidate the fast. This is because the oil enters the body through pores in the skin and this is not from the mediums that invalidate the fast. It is stated in Fataawa-Alamgiri:

Translation: The oil that enters through the pores of the body does not break the fast. (Fataawa Alamgiri, Volume 2, Page No. 21 Book of Fasting Siddiqui & Company Delhi) Also, it is stated in Fataawa Shaami:

Translation: "If a person applies oils, Surma or performs cupping then these will not invalidate or break the fast, although it is possible that the person may taste the oil in the throat, but then too it will still not break the fast as the taste reached the throat through absorption and combining with the body’s natural secretions. This taste did not reach the throat via the oral route. If it reaches beyond the throat by entering directly through the oral route then this would invalidate the fast. The Ulama unanimously agree on this point through analogy with a person bathing and that the satisfaction of the coolness of the water which is experienced both internally and externally it will not break or invalidate the fast". (Fataawa Shaami, Volume 4, Page 73, Book of Fasting - Zia-ul-Quran Publications, Lahore) One has to take note that the words found in Fataawa Shaami clarifies the concept that what is felt in the throat, and that which comes in the form of saliva, appears through secretions by the body, so it is not one of the nullifications which would break the fast. The medium which nullifies or breaks the fast is the one that reaches the brain or stomach from a passage other than the pores of the skin or veins. And in the case of vaccines or injections, the medicine that enters the body reaches via the skin and not by passing beyond the Manfadh (throat passage or route). This is the reason why in this regard, Hazrat Mufti Jalaalud’deen Ahmad Amjadi (may Allah have mercy on him) wrote in his authentic book Fataawa Faizur Rasool: "Thus, research shows that injections do not break the fast, whether injected into a vein or in to the flesh, because the general and universal regulation in this regard is that apart from intercourse and those things directly related to it, it is only that medicine and food that breaks the fast which reaches the brain or stomach from a passage other than pores and veins. (Fataawa Faiz-ur-Rasool, Vol. I, Pg 516)

The Summary: It is permissible to take the flu vaccine or injection while one is fasting, whether it is taken in a vein or in the flesh of the body. In both instances, the fast will not be invalidated.