How does the human body’s immune system change in space?

Our immune system is vulnerable to the rigours of space. During missions, astronauts undergo the effects of the exposure to harsh environmental conditions such as microgravity, heavy radiation, variable magnetic fields, altered circadian rhythms, lack of movement and isolation as well as altered immune functions and increased vulnerability to infections during and after flights.

In general the examination of the status of the astronauts’ immune systems reveals that there is a conversion from primed immune activity after acute gravitational stress to a progressive decay of the functionality of the immune system after several days of spaceflight – the longer the time spent out of Earth, the higher the effects on the immune system. These alterations progressively return to normal levels up to one year after return.

This represents a reality that should be more comprehensively analysed to ensure the feasibility of eventual long-range expeditions to the Moon, asteroids or other planets. To date only 24 astronauts have been beyond low-Earth orbit, thus the real consequences of long space travelling in human immunity remain largely unknown. Reducing the uncertainties in the adaptation of the immune system to long space flights is necessary before launching manned missions to interplanetary space. Jorge Domínguez Andrés is a research associate at the Radboud University Nijmegen Medical Center, The Netherlands

“Our immune system is vulnerable to the rigours of space”

Jorge Domínguez Andrés

Below: The night sky today is stunning, but imagine what it was like 10 billion years ago

Right: Almost half of the Apollo crew members suffered from an infection of sorts during, or up to seven days after their missions