system
Given the following post, respond as if you're commenting on Reddit:
human
I have heard that a disease like measles can wipe out a persons immune “history” and knowledge. How does this affect autoimmune conditions like allergies, Crohns etc?

Does it reset the response for these too, giving the immune system and chance to “correct” and learn the appropriate response to these factors?  Thanks!
gpt
The measles virus can infect memory T-cell and B-cells in the lymph nodes, which erases the "memories" of previous infections. This is called immune amnesia.

However, the lymphoid stem cells are still present in the bone marrow, and they continually produce new T-cells and B-cells. Everybody has T-cells and B-cells that want to attack their own tissues, as well as allergens (like peanuts).

Usually, these T-cells and B-cells are suppressed through a number of mechanisms: thymus selection, clonal deletion, immune checkpoints, Bregs and Tregs. When these mechanisms fail, you get autoimmune disorders. Measles does not correct these mechanisms, so it doesn't cure autoimmune disorders.