M. Garcia Knight - Virological, Immunological results after SARS-CoV-2 infection in household cohort

Early events in the natural history of SARS-CoV-2 infections define disease pathology, immune responses and viral transmission dynamics. We have leveraged a longitudinal household cohort of participants recruited in the San Francisco Bay Area, USA, since September 2020 to study key virological and immunological outcomes of infection. Nasal and saliva specimens collected intensely over a month enabled detailed characterisation of viral shedding dynamics of distinct viral variants in the context of varied vaccination histories. In addition, we characterised the kinetics of the neutralizing antibody (NAb) response targeting distinct viral variants (inducing omicron BA.1 and BA.2) over a month in unvaccinated participants and in those with vaccine breakthrough infections (VBI). We assessed the impact of pre-existing NAbs on viral shedding after VBI. Furthermore, we assess the influence of viral replication on the development of the anamnestic NAb response following VBI and the influence of immune imprinting on the development of de novo NAb responses. Our findings have implications for the protective effect of neutralizing antibody titers against the transmission of SARS-CoV-2 immune escape variants and shed light on
how viral replication influences the development of hybrid immunity.