It is recommended not to take a bath immediately after vaccination for the following reasons: 1. If a person takes a bath, the sewage from the bath will enter the subcutaneous tissue through the local puncture needle, thus carrying some bacteria to invade the subcutaneous soft tissue, which may lead to local redness, swelling, heat, pain and even pus at the later stage of the infection. 2. If the bath is a hot bath, it will promote blood circulation throughout the body, which may aggravate the symptoms of these reactions. If a person’s body has a reaction to the vaccine or even an allergic reaction, it is possible that the symptoms of these reactions will be aggravated. If the allergic reaction is strong, it may lead to shock, which may be life-threatening. 3.It is possible to promote the blood circulation of the local needle opening by taking a hot bath all over the body, which may lead to local subcutaneous bleeding.