Table 1 Discretized laboratory-confirmed COVID-19 infection history levels for first and second booster uptake

COVID-naïve

No infection before first booster or end date^a

No infection before second booster or end date^b

At least 1 infection before

At least 1 infection before PC

At least 1 infection before 1st booster

1 infection after

1 infection between PC and 1st booster or end date^a

1 infection between 1st booster and 2nd booster or end date^b

> 1 infection after

More than 1 infection between PC and 1st booster or end date^a

More than 1 infection between 1st booster and 2nd booster or end date^b

> 1 infection before and after

More than one infection until first booster or end date^a, before as well as after PC

More than one infection until end date^b, before as well as after 1st booster