Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures

Abstract

Cold-chain environment could extend the survival duration of SARS-CoV-2 and increases the risk of transmission. However, the effect of clod-chain environmental factors and packaging materials on SARS-CoV-2 stability and the efficacy of intervention measures to inactivate SARS-CoV-2 under cold-chain environment remains uncertain. This study aimed to unravel cold-chain environmental factors that preserved the stability of SARS-CoV-2 and disinfection measures against SARS-CoV-2 under the cold-chain environment. The spike gene of SARS-CoV-2 isolated from Wuhan hu-1 was used to construct the SARS-CoV-2 pseudovirus and used as model of the SARS-CoV-2 virus. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, various types of packaging material surfaces i.e., PE plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of LED visible light(wavelength 450 nm-780 nm) and airflow movement on the stability of SARS-CoV-2 pseudovirus at -18°C were subsequently assessed. The results show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surface compared with the non-porous surfaces including PE plastic, stainless steel and Teflon. Compared with 25°C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperature. Seawater preserved viral stability both at -18°C and repeated freeze-thawing cycles compared with deionized water. LED visible light illumination and airflow movement environment at -18°C reduced the SARS-CoV-2 pseudovirus stability. In conclusion, our results indicate cold-chain temperature and seawater as risk factors for SARS-CoV-2 transmission and LED visible light illumination and airflow movement as possible disinfection measures of SARS-CoV-2 under the cold-chain environment.

Evidence that the SARS-CoV-2 S protein undergoes a conformational change at the Golgi Complex that leads to the formation of virus neutralising antibody binding epitopes in the S1 protein subunit.

“…In cells expressing the recombinant S protein we employed two established commercial antibodies with which to compare with the PD5 and sc23 antibodies, these recognise the Nterminal domain (anti-NTD) and the RBD (anti-RBD) in the S1 protein subunit. The anti-NTD and anti-RBD antibodies have been previously used by others to examine and confirm S protein expression using different experimental systems [20][21][22]. The anti-NTD and anti-RBD antibodies were produced by using synthetic peptides from sequences in the region of the S protein at Proline25 (in the S1 subunit N-terminal domain) and Serine459 (in and the RBD).…”