The Immuno-2 experiment continues with research relating to the functioning of the immune system when humans spend prolonged periods in space. Besides microgravity and radiation, a variety of stress factors such as isolation, heavy workloads and disruption of sleep rhythms can weaken the immune system. On Earth, healthy and, in particular, critically ill people have to cope with comparable problems with their immune system, in some cases triggered by these very stress factors. In both cases, the subjects should be able to put up a sufficient defence against germs, but the immune system should not be falsely activated or over-activated.
Immuno-2 takes a holistic approach that combines biochemical analysis with psychological tests in order to correlate changes to the immune system and hormone levels of ISS astronauts with their stress levels. Comparisons with isolation and bed rest studies provide insights into the role of the individual factors causing imbalance of the immune system as well as findings relating to the mechanisms of the cellular immune system in general. This information is a prerequisite for the development of new preventive and therapeutic measures for treating astronauts and looking after the seriously ill in intensive care.
Advances in the holistic understanding of the relationship between stress and the immune system are significant for members of today's 'generation burn-out', but they are also of particular importance to patients in intensive care. According to the Federal Institute for Occupational Safety and Health (BAuA), the gross shortfall due to incapacity for work in 2015 amounted to 113 billion euros for Germany alone. Over the last ten years, the number of people suffering from mental illnesses almost doubled. Due to their long average duration, mental illnesses account for a considerable share of the economic losses. With the help of projects on the ISS and on Earth, scientists are trying to uncover the causes of stress-related illnesses and develop effective countermeasures.