Barcoded SARS-CoV-2 viruses define the impact of duration and route of exposure on the transmission bottleneck in a hamster model.

The transmission bottleneck, defined as the number of viruses shed from one host to infect another, is an important determinant of the rate of virus evolution and the level of immunity required to protect against virus transmission. Despite its importance, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission bottleneck remains poorly characterized. We adapted a SARS-CoV-2 reverse genetics system to generate a pool of >200 isogenic SARS-CoV-2 viruses harboring specific 6-nucleotide barcodes, infected donor hamsters with this pool, and exposed contact hamsters to paired infected donors, varying the duration and route of exposure.

Defining a highly conserved B cell epitope in the receptor binding motif of SARS-CoV-2 spike glycoprotein.

SARS-CoV-2 mRNA vaccines induce robust and persistent germinal centre (GC) B cell responses in humans. It remains unclear how the continuous evolution of the virus impacts the breadth of the induced GC B cell response. Using ultrasound-guided fine needle aspiration, we examined draining lymph nodes of nine healthy adults following bivalent booster immunization.

Immunogenicity and efficacy of XBB.1.5 rS vaccine against the EG.5.1 variant of SARS-CoV-2 in Syrian hamsters.

Unlabelled: The continued emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants necessitates updating coronavirus disease 2019 (COVID-19) vaccines to match circulating strains. The immunogenicity and efficacy of these vaccines must be tested in pre-clinical animal models. In Syrian hamsters, we measured the humoral and cellular immune response after immunization with the nanoparticle recombinant Spike (S) protein-based COVID-19 vaccine (Novavax, Inc.

Mucosal immunization with ChAd-SARS-CoV-2-S prevents sequential transmission of SARS-CoV-2 to unvaccinated hamsters.

COVID-19 vaccines have successfully reduced severe disease and death after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Nonetheless, COVID-19 vaccines are variably effective in preventing transmission and symptomatic SARS-CoV-2 infection. Here, we evaluated the impact of mucosal or intramuscular vaccine immunization on airborne infection and transmission of SARS-CoV-2 in Syrian hamsters.

Barcoded SARS-CoV-2 viruses define the impact of time and route of transmission on the transmission bottleneck in a Syrian hamster model.

The transmission bottleneck, defined as the number of viruses that transmit from one host to infect another, is an important determinant of the rate of virus evolution and the level of immunity required to protect against virus transmission. Despite its importance, SARS-CoV-2's transmission bottleneck remains poorly characterized, in part due to a lack of quantitative measurement tools. To address this, we adapted a SARS-CoV-2 reverse genetics system to generate a pool of >200 isogenic SARS-CoV-2 viruses harboring specific 6-nucleotide barcodes inserted in ORF10, a non-translated ORF.