Changes in the immune system during and after spaceflight

Publisher Summary This chapter discusses the changes in the immune system during and after spaceflight. Spaceflight represents an unusual occupation that demands uncommon activities to be performed in a unique environment. This exceptional combination of environment and activity is considered to cause measurable changes in the immune mechanism of humans and animal surrogates. The investigations of immunological analyses before, during, and after spaceflight, have established the fact that spaceflight can result in a blunting of the immune mechanism of human crew members and animal test species. The immune function changes in short-term flights resembles those occurring after acute stress, while the changes during long-term flights resemble those caused by chronic stress. This blunting of the immune function occurs concomitant with a relative increase in potentially infectious microorganisms in the space cabin environment. This combination of events results in an increased probability of inflight infectious events.