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Relative risk of SARS-CoV-2 infection by exposure status. The incidence rate ratio (95% CI) for SARS-CoV-2 infection by exposure status compared with the indicated referent group is shown for any SARS-CoV-2 infection (detected either clinically or via study surveillance PCR, left panel) or for clinically manifest COVID-19 only (right panel). N/E, nonestimable; ref, referent.
