The Centers for Disease Control and Prevention (CDC) states some people who had severe illness with COVID-19 experience multi-organ effects or autoimmune conditions over a longer time with symptoms lasting weeks or months after COVID-19 illness. Multi-organ effects can affect most, if not all, body systems, including heart, lung, kidney, skin, and brain functions. Autoimmune conditions happen when your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) or tissue damage in the affected parts of the body. While it is very rare, some people, mostly children, experience multisystem inflammatory syndrome (MIS) during or immediately after a COVID-19 infection. MIS is a condition where different body parts can become inflamed. MIS can lead to post-COVID conditions if a person continues to experience multi-organ effects or other symptoms. Source: https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects.html