Contingency table for HA re-infections with common HA clades.

Rows represent the HA clade in the first detected infection and columns the HA clade from an infection retrieved ≥7 days later (i.e. long lag). The number in each cell represents the number of cases, the standardized Pearson's residuals are provided in brackets.行代表首次检测到感染时的血凝素分支（Hemagglutinin clade, HA clade），列代表间隔≥7天（即长间隔）后检出的感染对应的血凝素分支。每个单元格内的数值代表病例数，括号中给出了标准化皮尔逊残差。