Can Reactivation of SARS-CoV-2 Decrease the Chance of Success of Future Deep Space Missions?

Korean CDC experts first reported the likelihood of reactivation in COVIOD-19 patients. They hypothesized that like childhood chicken pox infections which lie dormant for tens of years only to cause shingles in seniors, SARS-CoV-2 can reactivate. However, as testing for the virus had been flawed at that time, U.S. infectious disease experts were skeptical about the reports of second COVID-19 infections. New reports have addressed the urgent need to conduct large-scale studies to better understand the potential recurrence of SARS-CoV-2 in COVID-19 patients. Moreover, some case studies show possible reactivation of SARS-CoV-2 in a family cluster. Given this consideration, major space stressors such as microgravity and space radiation and their interactions which are not fully known, so far can increase the risk of reactivation of SARS-CoV-2 in future space missions, an event that can easily impact the success of any space mission. Since about 80% of infected people are either asymptomatic or show only mild symptoms, in a near future, it would be likely that astronauts who start their mission even after complex medical examinations, experience reactivation of the virus during their mission. Moreover, we have previously addressed the potential higher fatality of COVID-19 infections in space due to: 1) uselessness of social distancing due to microgravity; 2) immune system dysregulation; 3) possibly higher mutation rates of the novel coronavirus (SARS-CoV-2) as a RNA virus; 4) higher risk of reactivation of the virus; 5) existence of strong selective pressure and 6) decreased maximum oxygen uptake.