Redness and swelling of the skin after tuberculosis vaccination may be a common phenomenon, or it may be a localized infection. 1. Common phenomenon: Tuberculosis vaccine is BCG vaccine, is a live attenuated bacterial vaccine, into the body has the ability to reproduce itself, and then stimulate the body to produce antibodies, the pathogen to produce long-lasting immunity. Redness and swelling of the skin at the site of vaccination is a common phenomenon, usually without special treatment. It will disappear in a week or so. 2. Localized infection: After the tuberculosis vaccination, if you don’t pay attention to the cleanliness of the injection site, such as contact with pollutants or water, you may have localized infection resulting in arm pain, redness and swelling and other symptoms. After receiving the TB vaccine, you should observe the vaccine for 30 minutes before leaving, so as to avoid the emergence of undesirable side effects. If you feel unwell, you should consult a doctor in time, and under the guidance of the doctor to identify the cause of the disease and then actively treat it.