Environmental drivers of SARS-CoV-2 Omicron XBB.1.16.1 persistence on cold chain substrates

Background Some studies showed that stability of virus on the surfaces of inanimate materials could play a potential role in transmission; these findings have driven the further investigation of virus stability on the surfaces of inanimate materials under environmental conditions. The present study was performed on the effects of environmental factors on virus activity on the surfaces of packaging and food materials, so as to provide basic data and a scientific basis for the prevention and control of respiratory virus. Methods This study systematically investigated the environmental persistence of SARS-CoV-2 Omicron XBB.1.16.1 on cold chain substrates under multifactorial conditions. Controlled experiments evaluated temperature (−40°C to 15°C), relative humidity (RH: <40%, 40–70%, >70%), and temporal progression (0-90 days) using TCID ₅₀ assays in Vero E6 cells under Biosafety Level-3 (BSL-3) conditions. Substrates comprised porous and non-porous packaging materials (A4 paper and acrylonitrile butadiene styrene, ABS), while food matrices included livestock, seafood, and fruit-based products. Multivariate adaptive regression splines identified main and interactions effects among variables. Results Results demonstrated significant synergistic effects of temperatures (p<0.001), RH (p=0.003), and temporal progression (p<0.001) on viral decay kinetics. Packaging porosity showed no differential impact (p=0.871), while food substrate composition critically influenced persistence (p<0.001), with livestock products exhibiting 1.8-fold longer viral half-lives than fruit-based materials. In seafood, temperature-temporal interactions dominated titer reduction (p<0.001), independent of salinity (p=0.539). Infectious virus remained detectable for 90 days at ≤−20°C, with optimal stability observed under high RH (>70%) in packaging environments (p=0.006). Conclusion These findings highlight SARS-CoV-2’s prolonged viability under refrigeration and freezing conditions, emphasizing cold chain-mediated inanimate transmission risks. Substrate-specific persistence patterns and temperature-driven inactivation dynamics provide actionable insights for optimizing disinfection protocols and temperature control in logistics systems to mitigate viral dissemination.