“Most of us have viruses sleeping inside us, and spaceflight wakes them up’
Neel V. Patel. March 22, 2019
A study published in Frontiers in Microbiology has reported that herpes viruses that lie dormant in the body become activated in astronauts sent into space. Immune systems are known to take a hit from the effects of microgravity and living in small, confined spaces, so the addition of reactivated herpes viruses may make a high risk environment even more risky. The stress induced by the environment weakens the immune system to a level where dormant viruses are able to thrive.
Although virus reactivation does not necessarily mean the subject is sick, it certainly puts the subject at a greater risk of getting sick while the immune system is temporarily compromised.
Virus are nearly impossible to completely eradicate from the body, and immune-compromised individuals are at risk of viral infections due to the inability of their body to subdue any viral or pathogenic bacterial infections.
It has been well documented that stressful environments can temporarily weaken the immune system, leaving the subject vulnerable to viral or bacterial infections. Space travel is certainly a stressful environment, with the presence of microgravity, radiation, and high G forces on launch. While herpes viruses are not a good thing, as they are the cause of many sicknesses including shingles and mononucleosis, there are likely more worrisome and possibly life threatening infections in the body that may flourish in an immune-compromised individual. This is just one more barrier to the idea of long distance space travel, as an infection could be easily passed among a crew living in confined spaces, especially when the subjects are immune-compromised.
Although the level of viral shedding was increased, what factors affect when or how people become sick from these viruses, and is there a way to control that so even if the virus is active, it could not make the person sick?