Structural stability of SARS-CoV-2 degrades with temperature

Abstract

SARS-CoV-2 is a novel coronavirus which has caused the COVID-19 pandemic. Other known coronaviruses show a strong pattern of seasonality, with the infection cases in humans being more prominent in winter. Although several plausible origins of such seasonal variability have been proposed, its mechanism is unclear. SARS-CoV-2 is transmitted via airborne droplets ejected from the upper respiratory tract of the infected individuals. It has been reported that SARS-CoV-2 can remain infectious for hours on surfaces. As such, the stability of viral particles both in liquid droplets as well as dried on surfaces is essential for infectivity. Here we have used atomic force microscopy to examine the structural stability of individual SARS-CoV-2 virus like particles at different temperatures. We demonstrate that even a mild temperature increase, commensurate with what is common for summer warming, leads to dramatic disruption of viral structural stability, especially when the heat is applied in the dry state. This is consistent with other existing non-mechanistic studies of viral infectivity, provides a single particle perspective on viral seasonality, and strengthens the case for a resurgence of COVID-19 in winter.

Evolution and spread of SARS-CoV-2 likely to be affected by climate

“…It is known that SARS-CoV-1 was not able to survive in regions with warm climate as its lipid bilayer was prone to degradation at higher temperature 43 and it loses its viability at higher temperature 4 . A recent study shows the structural stability of SARS-CoV-2 Virus Like Particles (VLPs) degrades on increasing temperature 44 , supporting our observations.…”

Possible effects of air temperature on COVID‐19 disease severity and transmission rates

“…[1][2][3][4][5][6][7][8][9][10] The rate of exponential decay increases with temperature as heat denatures the proteins that comprise the SARS-CoV-2 virion. [1][2][3][5][6][7][8][9][10] The SARS-CoV-2 spike protein-which is necessary for cell entry-is temperature-dependent, in relation to the temperature required for optimal virus replication. 22 SARS-CoV-2 spike proteins exhibit temperature preference to match the upper (~33°C) airways over lower (37°C) airways, with further reductions in infectivity found as temperature increases to fever levels (41°C).…”

“…The stability of viruses is affected by changes in temperature, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID- 19), is no exception. [1][2][3][4][5][6][7][8][9][10] Heat denatures the proteins that comprise each SARS-CoV-2 virion, inactivating it. 3,8 Laboratory data indicate that, as temperatures increase, the rate at which virions are inactivated increases exponentially.…”

“…[1][2][3][4][5][6][7][8][9][10] Heat denatures the proteins that comprise each SARS-CoV-2 virion, inactivating it. 3,8 Laboratory data indicate that, as temperatures increase, the rate at which virions are inactivated increases exponentially. 3,9 These in vitro data suggest that lower temperatures within the body might result in lower rates of thermal inactivation and therefore higher rates of viral growth, potentially affecting viral shedding, viral load densities, transmission rates, and patient outcomes.…”

Possible Effects of Air Temperature on COVID-19 Disease Severity and Transmission Rates

“…The stability of viruses is affected by changes in temperature, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID- 19), is no exception. [1][2][3][4][5][6][7][8][9][10] Heat denatures the proteins that comprise each SARS-CoV-2 virion, inactivating it. 3,8 Laboratory data indicate that, as temperatures increase, the rate at which virions are inactivated increases exponentially.…”