A new study published in the Journal of Applied Physiology has found that space flight does not affect a major part of the immune system as previously thought, potentially changing the way researchers look at future missions.
The results were achieved by taking blood from 23 crew members of the International Space Station who had spent six months at the ISS during 18 separate missions. The study subjects were between the ages of 37 and 57. The blood samples were taken before, during and after the missions, and the space samples were sent down to Earth in the Russian Soyuz descent capsules. For a control group, researchers also took samples from six ground-based subjects.
Researchers were looking at the white blood cells that make antibodies that are activated when an infection is present to fight it off – the so called B-cell immunity levels. They found that there were no changes during the crew members’ time in space.
“This is the first study to comprehensively show that long-duration space flight in human astronauts has a limited effect on B-cell frequency and antibody production,” said Dr. John Campbell, a lecturer at the University of Bath. “Our results are good news for current astronauts aboard the ISS ... and for all future astronauts who will attempt long-duration space missions.”
Immunity is important for two reasons. First, astronauts should have the optimal B-cell immunity to be protected from diseases caused by viruses or bacteria. Second, immunity is crucial to the effectiveness of vaccines that astronauts receive in space.
“Long-duration orbital space flights are associated with increased levels of psychological stress, acute and chronic exposure to space radiation and microgravity-induced changes, all of which are known to detrimentally impact the immune system,” said Dr. Guillaume Spielmann from Louisiana State University.
The implications of this study include the possibility of astronauts going on longer missions, including, eventually, to Mars.
Photo credit: Roscosmos