RT Journal Article
SR Electronic
T1 SARS-CoV-2 Omicron-B.1.1.529 Variant leads to less severe disease than Pango B and Delta variants strains in a mouse model of severe COVID-19
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.12.26.474085
DO 10.1101/2021.12.26.474085
A1 Eleanor G. Bentley
A1 Adam Kirby
A1 Parul Sharma
A1 Anja Kipar
A1 Daniele F. Mega
A1 Chloe Bramwell
A1 Rebekah Penrice-Randal
A1 Tessa Prince
A1 Jonathan C. Brown
A1 Jie Zhou
A1 Gavin R. Screaton
A1 Wendy S. Barclay
A1 Andrew Owen
A1 Julian A. Hiscox
A1 James P. Stewart
YR 2021
UL http://biorxiv.org/content/early/2021/12/28/2021.12.26.474085.abstract
AB COVID-19 is a spectrum of clinical symptoms in humans caused by infection with SARS-CoV-2. The B.1.1.529 Omicron variant is rapidly emerging and has been designated a Variant of Concern (VOC). The variant is highly transmissible and partially or fully evades a spectrum of neutralising antibodies due to a high number of substitutions in the spike glycoprotein. A major question is the relative severity of disease caused by the Omicron variant compared with previous and currently circulating variants of SARS-CoV-2. To address this, a mouse model of infection that recapitulates severe disease in humans, K18-hACE2 mice, were infected with either a Pango B, Delta or Omicron variant of SARS-CoV-2 and their relative pathogenesis compared. In contrast to mice infected with Pango B and Delta variant viruses, those infected with the Omicron variant had less severe clinical signs (weight loss), showed recovery and had a lower virus load in both the lower and upper respiratory tract. This is also reflected by less extensive inflammatory processes in the lungs. Although T cell epitopes may be conserved, the antigenic diversity of Omicron from previous variants would suggest that a change in vaccine may be required to mitigate against the higher transmissibility and global disease burden. However, the lead time to develop such a response may be too late to mitigate the spread and effects of Omicron. These animal model data suggest the clinical consequences of infection with the Omicron variant may be less severe but the higher transmissibility could still place huge burden upon healthcare systems even if a lower proportion of infected patients are hospitalised.Competing Interest StatementThe authors have declared no competing interest.