Everything that you mentioned plays a role the immune system. Genetics is an important variable. Some people genetically have stronger immune responses that protect them from infection. Some people have genetic variations that cause them to be more prone to autoimmune diseases. There is a scientific journal titled Genes and Immunity that focuses on this topic.
Jumpin_Jo t1_j8c7o9y wrote
Reply to What makes a strong immune system? by hodlboo
Everything that you mentioned plays a role the immune system. Genetics is an important variable. Some people genetically have stronger immune responses that protect them from infection. Some people have genetic variations that cause them to be more prone to autoimmune diseases. There is a scientific journal titled Genes and Immunity that focuses on this topic.