Risk of hospital admission and death from first-ever SARS-CoV-2 infection by age group during the Delta and Omicron periods in British Columbia, Canada

Risk of hospital admission and death from first-ever SARS-CoV-2 infection by age group during the Delta and Omicron periods in British Columbia, Canada Research Risk of hospital admission and death from first-ever SARS-CoV-2 infection by age group during the Delta and Omicron periods in British Columbia, Canada Danuta M. [...] Analyses of severe out- health authority and intersurvey period, with Bayesian-adjusted comes were undertaken under the BCCDC population health sur- median estimates applied to 2022 estimates of the Lower Main- veillance and risk assessment mandate, with review waiver land population to generate the number of first infections.32 We provided by the University of British Columbia Clinical Research c. [...] We tallied severe out- We describe provincial vaccine availability, deployment and comes across intersurvey periods, which spanned the period coverage in Appendix 1, Supplementary Material 2.40 Overall, 1- from the beginning of 1 serosurvey to the end of the complete and 2-dose vaccine coverage was already high by the sixth sero- epidemiological week of a referent date 2 weeks before the last surv. [...] We could not estimate IHR and IFR for the ninth to were also representative of the Lower Mainland source popula- tenth intersurvey period because of incomplete data on hospital tion (Table 2 and Appendix 1, Supplementary Table 5 and Sup- admissions and deaths. [...] In the context of high tion impact of COVID-19 by age is also determined by the abso- vaccine coverage contributing to hybrid protection, most children lute size of the age cohort and the likelihood of having been, or and adults were at low risk of severe outcomes from COVID-19.