Table 1.

Population and infection-related incidence of SARS-CoV-2 associated intensive care unit admissions in paediatric and young adult cohorts^a, across three SARS-CoV-2 variant eras in Australia.

Age group (years)	Pre-Delta (Jan 1 2020–May 31 2021)			Delta (1 Jun 2021–30 Nov 2021)			Omicron (1 Dec 2021–end June 2022)
	ICU admissions	Age specific annualised population incidence (per 100,000b)	Infection-related incidence (per 1000 SARS-CoV-2 notificationsd)	ICU admissions	Age specific annualised population incidence (per 100,000c)	Infection-related incidence (per 1000 SARS-CoV-2 notificationd)	ICU admissions	Age specific annualised population incidence (per 100,000c)	Infection-related incidence (per 1000 SARS-CoV-2 infection notificationsd)
<2	4	0.9 (0.2–2.3)	10.8 (2.9–27.5)	4	2.6 (0.7–6.7)	0.9 (0.2–2.2)	55	30.9 (23.2–40.2)	0.47 (0.35–0.61)
2–4	0	0.0 (0–0.5)	0.0 (0–7.3)	5	2.1 (0.7–5.0)	0.6 (0.2–1.4)	35	12.7 (8.9–17.7)	0.17 (0.12–0.24)
5–11	2	0.1 (0–0.4)	1.6 (0.2–5.7)	7	1.2 (0.5–2.5)	0.3 (0.1–0.6)	41	6.0 (4.3–8.2)	0.06 (0.04–0.08)
12–15	0	0.0 (0–0.4)	0.0 (0–4.1)	15	4.6 (2.5–7.5)	1.3 (0.8–2.2)	30	7.8 (5.3–11.1)	0.07 (0.05–0.10)
16–17	2	0.5 (0.1–1.7)	3.6 (0.4–12.8)	9	5.9 (2.7–11.2)	1.7 (0.8–3.2)	12	6.8 (3.5–11.8)	0.06 (0.03–0.11)
18–25	13	0.7 (0.4–1.1)	2.7 (1.4–4.6)	80	12.2 (9.6–15.1)	2.9 (2.3–3.6)	96	12.5 (10.1–15.3)	0.10 (0.08–0.12)

Abbreviations: ICU: intensive care unit; NNDSS: national notifiable disease surveillance system; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.

^aPaediatric is < 18 years and young adult is 18–25 years.

^b2020 mid-year population estimates from Australian Bureau of Statistics adjusted for duration of surveillance in months.

^c2021 mid-year population estimates from Australian Bureau of Statistics adjusted for duration of surveillance in months.

^dAge-specific SARS-CoV-2 infection notification data provided by NNDSS data custodians.