We make antibodies, that's not the analogy I'm using, and I am studied in immunology. Some diseases are so harmful, our body keeps antibodies floating around pe

We make antibodies, that's not the analogy I'm using, and I am studied in immunology. Some diseases are so harmful, our body keeps antibodies floating around perpetually in case we encounter it (e.g. smallpox). Coronaviruses are mild enough that we can "remember" it with t-cells and spin up antibodies as needed. Part of what bones do is this antibody production process, and it requires more energy than vital organs.