Try not to take a shower after receiving the MMR vaccine, as showering may cause infections at the vaccination site or breaks in the rash. The MMR vaccine is a vaccine against measles, mumps and rubella. The MMR vaccine is usually given by intramuscular injection, so after vaccination, a needle mark will be left at the vaccination site, and if you take a shower at this time, the shower water may flow into the needle mark, which may cause infection at the vaccination site. If you accidentally rub the vaccination site when bathing, it may aggravate the redness, swelling, pain and other discomforts. Usually there is a slight rash after MMR vaccination, and bathing at this time may cause the rash to break, so bathing is not recommended.