My general lay-person understanding is that your immune system is less active when you sleep. While I hate the way we tend to overlook other elements of the imm

My general lay-person understanding is that your immune system is less active when you sleep. While I hate the way we tend to overlook other elements of the immune system and act like white blood cells are your entire immune system, in this case it may be very pertinent because white blood cells travel in the blood. They may basically be going out into the blood when there are fewer white blood cells roaming the corridors, looking to kill something.