Shorter serial intervals in SARS-CoV-2 cases with Omicron BA.1 variant compared to Delta variant in the Netherlands, 13 – 26 December 2021

Abstract

Abstract The SARS-CoV-2 Omicron variant has a growth advantage over the Delta variant, due to higher transmissibility, immune evasion, or a shorter serial interval. Using S-gene target failure (SGTF) as indication for Omicron BA.1, we identify 908 SGTF and 1621 non-SGTF serial intervals in the same period. Within households, we find that the mean serial interval for SGTF cases is 0.2-0.6 days shorter than for non-SGTF cases. This suggests that the growth advantage of Omicron is partly due to a shorter serial interval.