Characterisation of vaccine breakthrough infections of SARS-CoV-2 Delta and Alpha variants and within-host viral load dynamics in the community, France, June to July 2021

摘要

We compared PCR results from SARS-CoV-2-positive patients tested in the community in France from 14 June to 30 July 2021. In asymptomatic individuals, Cq values were significantly higher in fully vaccinated than non-fully vaccinated individuals (effect size: 1.7; 95% CI: 1–2.3; p?&?10 ~(?6)). In symptomatic individuals and controlling for time since symptoms, the difference vanished (p?=?0.26). Infections with the Delta variant had lower Cq values at symptom onset than with Alpha (effect size: ?3.32; 95% CI: ?4.38 to ?2.25; p?&?10 ~(?6)).