Infectious disease outcomes of NASA's health stabilization program.

To prevent pre-flight and on-orbit infections, NASA crew participate in a comprehensive Health Stabilization Program (HSP), which includes pre-flight quarantine, vaccination and demonstrated immunity, personal protective equipment, and crew and support personnel training. We aggregated historical spaceflight data to assess the incidence of pre-flight infectious exposures in spaceflight, to determine the effectiveness of HSP protocols, and to characterize risk factors associated with pre-flight exposure resulting in on-orbit illness. Medical and operational records on U.S. spaceflight missions from the Apollo Program through 2024 were retrospectively aggregated and analyzed. HSP-related mission-events were defined as an event where an identified failure, breach of protocol, or exposure occurred during the HSP/quarantine period resulting in one or more crewmember illnesses. In 196 aggregated spaceflight missions, 30 missions (15%) included infectious events among crew in the launch timeframe. In two missions (1%), launch of an ill crew further exposed additional on-orbit crews with infectious sequelae. Overall, launch delay due to crew infection occurred in two missions (1% of the aggregate cohort). While infectious events have occurred in spaceflight crew, HSP has resulted in overall mission success, with no HSP-related medical evacuations, no severe on-orbit medical sequelae, and no long-term health impacts related to HSP events.