Table.

Number of households, participants, and infections by variant

		Recruitment months, 2021	Number of households (n=227)	Number of participants (n=559)	Number of infections (n=417)
Alpha		February–May	131	334	243
	Confirmed	February–May	116	300	223
	Assumed	February–April	15	34	20
Delta		May–August	96	225	174
	Confirmed	May–June	27	61	55
	Assumed	June–August	69	164	119

In each household, the variant responsible for infections was either determined by genomic sequencing or assumed on the basis of the month in which the household index case first tested positive. Only a single variant was detected in each sequenced household (ie, no household had detected infections with both the alpha [B.1.1.7] and delta [B.1.617.2] variants). Sequencing data from July, 2021, onwards were not available at the time of our analysis, although the delta variant was dominant in this period.¹