The Impact of Space Travel on Astronauts' Immune System

A study involving 14 astronauts who spent 4½ to 6½ months aboard the International Space Station found that gene expression in white blood cells crucial to the immune system quickly decreased when they reached space and then returned to normal not long after returning to Earth. This weakened immunity increases the risk of infectious diseases limiting astronauts' ability to perform their very demanding work in space. The findings offer insight into why astronauts are more susceptible to infection during flights, showing how the body's system for fighting off pathogens is weakened in space.