The body’s immune reaction/response to viral or bacterial infection or injury and shows physically as any or all of the following; redness, swelling, pain, a feeling of heat, or loss of function in an area of the body.
Inflammation is a series of reactions that bring cells and molecules of the immune system to the site of infection or injury. Severe forms of COVID-19 are due to a hyper-reactive immune response that ends up damaging the tissues it is trying to protect. For example, some people with COVID-19 develop severe inflammation in their lungs and other organs.
Inflammation, such as mild redness and swelling at the site of vaccination (usually on the arm) is an indication that the vaccine is working.
Immune System Infectious Disease