ABSTRACT Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), is characterized by its high contagiousness. The COVID-19 pandemic has exerted profound impacts on human society . The persistent circulation of SARS-CoV-2 in human populations continues to pose re-exposure risks for both vaccinated individuals and those with prior natural infection. Against this epidemiological background, there is an urgent need to characterize the transmission dynamics of SARS-CoV-2 in the context of pre-existing immunity . Using a ferret infection model , this study systematically addresses critical scientific questions , including viral transmission efficiency , temporal patterns of transmissibility , and the ability of pre-existing immunity to mitigate reinfection and viral shedding. The findings provide robust experimental evidence for elucidating the transmission mechanisms of SARS-CoV-2 and offer scientific insights to info...
Media Monitoring for Signals about Emerging Threats