Spaceflight does not compromise major part of immune system, study finds
Astronauts spending extended periods of time in orbit will not compromise a major part of their immune system, according to research.
Scientists tested blood samples of crew members taken before, during and after a six-month mission on the International Space Station.
They detected no changes in B-cell immunity – the white blood cells that produce antibodies to fight off infections.
It had previously been thought that space flight had a detrimental effect on the immune system.
The research could help decide whether astronauts taking part in longer missions – such as travelling to Mars – should receive vaccines in space.
Dr John Campbell, of University of Bath’s Department for Health, said: “This is the first study to comprehensively show that long-duration spaceflight in human astronauts has limited effect on B-cell frequency and antibody production.
“Our results are good news for current astronauts aboard the ISS, including University of Bath alumna Lt Col Anne McClain, and for all future astronauts who will attempt long-duration space missions.”
The study, published in the Journal of Applied Physiology, focused on B-cells – an essential type of white blood cells responsible for producing antibodies to target harmful pathogens.
Having optimal B-cell immunity is crucial to ensuring long-term protection against disease-causing bacteria and viruses.
Researchers say it is also important for ensuring vaccinations are effective.
Until now, due to logistical constraints, the majority of space immunology has been conducted during short-duration missions or by comparing measures of immune function before and after flight.
But for this study, bloods from 23 astronauts were taken during their time on the ISS.
The samples were sent down to Earth by Russian Soyuz descent capsules, landing in Kazakhstan before being taken to Moscow, then flown to a lab in Houston.
This journey – from the ISS to Houston – usually took 32 to 48 hours.
Dr Guillaume Spielmann, from Louisiana State University, said: “Long-duration orbital spaceflights 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.
“However, the effects of spaceflight on B-cell immunity – a major arm of the immune system – have to date remained unclear.”
The blood samples were taken before the astronauts took off, three times during the flight, after they landed and during a recovery period.
Crew members involved in the study were aged between 37 and 57, with data collected over 18 separate ISS missions.
Researchers also took blood samples from six people who were ground-based, for a control group.