Emerging variants of SARS-CoV-2 have been shown to rapidly replace original circulating strains in humans soon after they emerged. There is a lack of experimental evidence to explain how these natural occurring variants spread more efficiently than existing strains of SARS-CoV-2 in transmission. We found that the Alpha variant (B.1.1.7) increased competitive fitness over earlier parental D614G lineages in in-vitro and in-vivo systems. Using hamster transmission model, we further demonstrated that the Alpha variant is able to replicate and shed more efficiently in the nasal cavity of hamsters than other variants with low dose and short duration of exposure. The capability to initiate effective infection with low inocula may be one of the key factors leading to the rapid transmission of emerging variants of SARS-CoV-2. Bobo Wing-Yee Mok et al. observe that the Alpha (B.1.1.7) variant of SARS-CoV-2 exhibits increased competitive fitness over earlier lineages at lower doses in a hamster model of viral transmission. Their results suggest that the Alpha variant’s ability to initiate effective infection with a low dose may underlie its ability to rapidly transmit throughout a population.
【저자키워드】 SARS-CoV-2, Viral transmission, 【초록키워드】 hamsters, Human, variant, Infection, Transmission, nasal, Spread, Viral, B.1.1.7, low dose, Lineage, D614G, Alpha, Viral transmission, Transmission model, Alpha variant, hamster, Nasal cavity, strain, In-vitro, other variants, short duration, circulating, key factor, lower dose, experimental evidence, variants of SARS-CoV-2, effective, variant of SARS-CoV-2, observé, shown, lack, replicate, demonstrated, parental, explain, exhibit, underlie, other variant, 【제목키워드】 variant, hamster, dose,