NASA is conducting research to determine how the human immune system changes during extended crewed spaceflight missions and how to “counterbalance” these changes through vaccination.1
The study is being led by investigator Emmanuel Mignot, MD, PhD, professor of psychiatry and behavioral sciences at Stanford University, as part of NASA’s Twins Study. It involves astronauts and identical twin brothers Scott and Mark Kelly—the former of which is currently aboard the orbiting International Space Station (ISS) on a one-year mission, which began on March 27, 2015, while the latter has remained on Earth.2 3
The research includes a series of experiments on the brothers to understand the “effects of prolonged spaceflight on human physiology, behavioral health, and microbiology, among other areas”2 in anticipation of possible missions to the Moon and Mars during the next two decades. According to Dr. Mignot:
We will be able to determine what portion and pathways of the immune system are most challenged by space flight. We’ll calibrate the amount of immune changes present and offer ideas on how to counterbalance it, for example using higher doses of vaccination for key viruses to avoid reactivation.2
The goal of the research is to determine whether, after a year in an isolated space environment, Commander Scott Kelly’s immune system responds less or more to vaccination, compared to that of his brother, particularly given factors such as work-related stress, being away from home and family for an extended period of time, exposure to radiation and a microgravity environment, and altered sleep cycles.1
One of the key differences that is being closely observed is that Commander Kelly in space is exposed to far less infectious agents, or pathogens, than his brother on the ground. The immune system’s exposure to pathogens results in the body producing a type of white blood cells called T-cells,2 which play a central role in the immune response to diseases. Dr. Mignot noted:
Vaccinations only protect against one agent, in this case the flu. So we can look at the specific T-cells that are recruited by the body to fight against the flu and see how the immune system responds.2
Each of the brothers were given flu shots and had bloodwork done prior to Commander Kelly’s launch to ISS, and then again six months into the mission. The process will be repeated again six months after Commander Scott Kelly’s planned return to Earth in March 2016.2
1 Blanchett A. Precision immunization: NASA studies immune response to flu vaccine in space and on Earth. Medical Express Dec. 23, 2015.
2 Watry G. Designing Effective Vaccines for Long-Term Spaceflight. R&D Magazine Dec. 23, 2015.
3 Redd NT. 6 Months in Space, Astronaut Scott Kelly Misses Food, Outdoors and Loved Ones. SPACE.com Sept. 18, 2015.