Fig. 3From: Retrospective analysis of SARS-CoV-2 omicron invasion over delta in French regions in 2021–22: a status-based multi-variant modelDistribution of \(\frac{\hat{R}_{\textrm{omicron}}}{\hat{R}_{\textrm{delta}}}\) by regions shown by a 40 bins histogram between the values 1 and 3, when varying the cross-immunity \(\epsilon\) and preimmunization level a (preinf). The generation time was 5 days for the delta variant and 3.5 days for the omicron variantBack to article page