I just read about a fascinating infectious disease experiment that is ongoing on the International Space Station. The experiment is focused on determining what effect being in space for a prolonged period will have on influenza vaccine response.
In this study, astronaut Scott Kelly and his Earth-bound twin Mark Kelly both will receive influenza vaccines at regular intervals and have the resulting immune response measured. As all immune systems in every species that possesses one on Earth involved in a gravity-laden setting, it is not surprising that the absence of gravity can alter function. For example, space is known to be a T-cell suppressing activity. Also, the environmental microbiological environment on the space station is one very different than that on Earth and that difference likely impacts immune function as well.
The nuanced changes in immune response to the flu vaccine will be fascinating to see unraveled. Such experiments will play a role in understanding T-cell function more fully, a crucial need in the quest to improve vaccines and understand the intricacies of the immune system.