Age-varying susceptibility to the Omicron variant (B.1.1.529) of SARS-CoV-2

Abstract The Omicron variant (B.1.1.529) is estimated to be more transmissible than previous strains of SARS-CoV-2 especially among children, potentially resulting in croup which is characteristic disease in children. However, there have been no reports confirming the relative susceptibility of different age groups to SARS-CoV-2. In this study, we estimated the age-specific susceptibility during the 5th (Omicron driven), 4th (Delta driven), and 3rd (pre-Delta) waves in South Korea, using the age-structured compartmental model. Even after adjusting for contact pattern, vaccination status, and waning of vaccine effectiveness, the susceptibility among age group 0–19 years was approximately 5 times higher during the 5th wave (Omicron driven) than that during the 3rd wave (pre-Delta), and 3 times higher than that during the 4th wave (Delta driven). Here, we found that children are indeed more susceptible to the Omicron variant compared with the previous strains of SARS-CoV-2.