Silent Reactivation of Varicella Zoster Virus in Pregnancy: Implications for Maintenance of Immunity to Varicella

Time-resolved molecular measurements reveal changes in astronauts during spaceflight

From the early days of spaceflight to current missions, astronauts continue to be exposed to multiple hazards that affect human health, including low gravity, high radiation, isolation during long-duration missions, a closed environment and distance from Earth. Their effects can lead to adverse physiological changes and necessitate countermeasure development and/or longitudinal monitoring. A time-resolved analysis of biological signals can detect and better characterize potential adverse events during spaceflight, ideally preventing them and maintaining astronauts' wellness. Here we provide a time-resolved assessment of the impact of spaceflight on multiple astronauts (n = 27) by studying multiple biochemical and immune measurements before, during, and after long-duration orbital spaceflight. We reveal space-associated changes of astronauts' physiology on both the individual level and across astronauts, including associations with bone resorption and kidney function, as well as immune-system dysregulation.

Time-resolved molecular measurements reveal changes in astronauts during spaceflight

From the early days of spaceflight to current missions, astronauts continue to be exposed to multiple hazards that affect human health, including low gravity, high radiation, isolation during long-duration missions, a closed environment and distance from Earth. Their effects can lead to adverse physiological changes and necessitate countermeasure development and/or longitudinal monitoring. A time-resolved analysis of biological signals can detect and better characterize potential adverse events during spaceflight, ideally preventing them and maintaining astronauts' wellness. Here we provide a time-resolved assessment of the impact of spaceflight on multiple astronauts (n=27) by studying multiple biochemical and immune measurements before, during, and after long-duration orbital spaceflight. We reveal space-associated changes of astronauts' physiology on both the individual level and across astronauts, including associations with bone resorption and kidney function, as well as immune-system dysregulation.

Varicella Vaccine: a Molecular Variant That May Contribute to Attenuation

Varicella was troublesome when varicella vaccine (vOka) was licensed in the United States. Varicella's yearly death toll was ~100, indirect costs were massive, and varicella threatened immunocompromised children. Since licensure, varicella has almost disappeared; nevertheless, vOka attenuation has lacked a molecular explanation. Sadaoka et al. (T. Sadaoka, D. P. Depledge, L. Rajbhandari, J. Breuer, et al., mBio 13:e0186422, 2022, https://doi.org/10.1128/mbio.01864-22), however, have now identified 6 core single nucleotide polymorphisms (SNPs), which singly or in combination may contribute to VOka attenuation; moreover, they found a predominant variant allele of vOka encoding the viral glycoprotein gB that results in glutamine instead of arginine at amino acid 699. This change impairs fusion activity and the ability of varicella-zoster virus (VZV) to infect human neurons from axon terminals. Molecular virological studies of vOka are reassuring in suggesting that reversion to virulence is unlikely and should also help assuage current fears about VZV vaccination and alleviate unanticipated future problems. The impressive work of Sadaoka et al. thus represents an auspicious advance in knowledge.