Space is an unforgiving environment. Anyone who has ever seen The Martian or read up on the health hazards of weightlessness knows the risks astronauts take when they sign up for an extended stay on the International Space Station: from bone density and muscle loss to exposure to space radiation, the time spent on the massive station (its solar array wingspan is around 240 feet long) -- exciting though it may be -- is not without risk. But what about germs?
When Immune Systems And Solar Systems Collide
A great and many studies have been performed on how the human body reacts to extended time spent in the near-weightlessness of space, including how gravity impacts and distorts cellular fluids. For example, earlier experimentation found that spaceflight boosts the virulence (the disease-causing potential) of the food-borne germ Salmonella; since space travel already weakens astronaut immunity, this places significantly more risk on the health of the astronauts.
"By studying the effect of spaceflight on the disease-causing potential of major pathogens like Salmonella, we may be able to provide insight into infectious disease mechanisms that cannot be attained using traditional experimental approaches on Earth, where gravity can mask key cellular responses," explained Cheryl Nickerson, who made the discovery with her colleagues.
Vaccines In Space
Vaccines operate by pre-activating T-cells; they are able to react faster to block development of the disease because these killer cells are already geared up to protect us from invaders. Our immune systems are bolstered as a result, and -- as Nickerson proved -- are still a necessity even on the ISS, where astronauts are exposed to fewer pathogens.
The most common (and one of the most important) is the influenza vaccine: it's estimated that as many as 710,000 flu-related hospitalizations have been prevented since 2010 due to the efficacy of inoculations, and since there are no hospitals on the ISS, their administering is vital to its residents' health. By studying how the human body, living in zero gravity, responds to immunizations, further developments can be made regarding long-term space travel; the better we can safeguard the immune systems of astronauts, the longer they'll be able to stay in space.
Advancements That Could Take Us To Mars
Compounding on this immunology finding is the work of Dr. John Campbell, a lecturer at the University of Bath, and his team: they've discovered that living in space does not alter an astronaut's levels of B-cell immunity, the white blood cells that create antibodies to fight off infections. B-cells are companions to T-cells, so their unaltered state offers extra protection from outside invaders.
"Our results are good news for current astronauts aboard the ISS … and for all future astronauts who will attempt long-duration space missions," said Dr. Campbell, hinting at the possibility of a trip to Mars; since the flight takes three years to complete (around three times longer than the U.S. current record set by astronaut Scott Kelly), this kind of knowledge could take us one step closer.