Why does the omicron variant largely spare olfactory function? Implications for the pathogenesis of anosmia in coronavirus disease 2019

R Butowt, K Bilińska… - The Journal of infectious …, 2022 - academic.oup.com
R Butowt, K Bilińska, C von Bartheld
The Journal of infectious diseases, 2022academic.oup.com
The omicron variant of severe acute respiratory syndrome coronavirus 2 causes much less
olfactory dysfunction than the previous variants. There are several potential mechanisms for
how omicron may change tissue tropism and spare olfactory function. The new mutations
make omicron more hydrophobic and alkaline than previous variants, which may reduce
penetration of the mucus layer. Overall, the new mutations minimally change receptor
binding affinity, but entry efficiency into host cells is reduced in cells expressing …
Abstract
The omicron variant of severe acute respiratory syndrome coronavirus 2 causes much less olfactory dysfunction than the previous variants. There are several potential mechanisms for how omicron may change tissue tropism and spare olfactory function. The new mutations make omicron more hydrophobic and alkaline than previous variants, which may reduce penetration of the mucus layer. Overall, the new mutations minimally change receptor binding affinity, but entry efficiency into host cells is reduced in cells expressing transmembrane serine protease 2 (TMPRSS2). Because the support cells in the olfactory epithelium abundantly express TMPRSS2, these main target cells in the olfactory epithelium may become infected less by the new omicron variant.
Oxford University Press