Falling ill while traveling is an unfortunate yet common occurrence. Even a minor bug can ruin an entire trip. But for astronauts, getting sick on a long space voyage would have far more serious consequences than a little spoiled fun. The Rodent Research 12 (RR-12); investigation joins a series of studies aboard the International Space Station with the common goal of keeping astronauts healthy in space.
Research has shown that spaceflight causes significant changes in the human immune system. These changes seem to depend on the length of time spent in space; more research is needed to confirm these findings and significance for long term health. Scientists also want to exactly how the immune system responds when exposed to a pathogen that can cause illness while in space. Mice have immune systems very similar to that of humans; so RR-12 is sending mice to the space station in an effort to answer that question.

The space station

Because infectious organisms are unwelcome on the space station; the researchers are using a vaccine that is similar to the one commonly used for tetanus to generate an antibody or immune response in the mice. The vaccine toxoid poses no risk to crew members because all have already received the same vaccine. One group of mice receives its first exposure to the vaccine after two weeks aboard the space station with researchers examining the number and type of antibodies produced as a result.

This part of the study helps determine if the immune system can respond to a challenge it has never seen before while in space. The investigators expect to see fewer immune cells and different types of them than the vaccine typically triggers; on the ground. The second set of mice receives the vaccine on the ground so it can develop an antibody response and immunological memory before flying to the space station; just as a person would after receiving a vaccination.

The immunological memory

The mice receive a second vaccination two weeks into the flight. This allows researchers to test whether immunological memory is effective in space by comparing; the responses in the two groups of mice. Because NASA is so careful with its astronauts; very few people get sick during spaceflight and it is not a major concern now,” Pecaut said. “But as we start sending astronauts on longer trips; or as opportunities for space commercialization or tourism ramp up; they need to know that the immune system is still effective.
They want to sure that astronauts can respond to an immune system challenge in space the same as on Earth.” This investigation, sponsored by NASA Space Life and Physical Science-Space Biology (NASA-SLPS-Space Biology); is the first time rodents have flown to the space station from NASA’s; Wallops Flight Facility aboard a Cygnus spacecraft. This mission tests a new late load capability, allowing time-sensitive experiments to be loaded into Cygnus just 24 hours before launch rather than the previous four-day requirement.