From the actual paper [1]: "The shedding did not abate during the longer ISS missions, but rather increased in frequency and amplitude. These findings coincided

From the actual paper [1]: "The shedding did not abate during the longer ISS missions, but rather increased in frequency and amplitude. These findings coincided with the immune system dysregulation observed in astronauts from shuttle and ISS missions." So it's not just ascent and descent. [1] https://www.frontiersin.org/articles/10.3389/fmicb.2019.00016/full https://www.frontiersin.org/articles/10.3389/fmicb.2019.0001...