Variable	With Stepwise BIC selection		Without Feature Selection
	Adjusted incidence rate ratio (95% CI)	P-value	Adjusted incidence rate ratio (95% CI)	P-value
The bi-weekly cumulative counts of 1st and 2nd vaccine doses in the age group 16–39, normalized by the respective population size	3.32 (2.12–5.14)	< 0.001	2.20 (1.06–4.56)	< 0.05
The three-week cumulative new COVID-19 infection count among the age group 16–39, normalized by the respective population size	–	–	26.94 (0.03–20,067.17)	0.330
Call type: Acute Coronary Syndrome	1 [Reference]	–	1 [Reference]	–
Call type: Cardiac arrest	0.24 (0.22–0.25)	< 0.001	0.24 (0.22–0.25)	< 0.001
Week not during a COVID-19 public health advisory	1 [Reference]	–	1 [Reference]	–
Week during a COVID-19 public health advisory	–	–	0.94 (0.85–1.04)	0.224
Year: 2019	0.88 (0.83–0.94)	< 0.001	0.83 (0.75–0.92)	< 0.001
Year: 2020	–	–	0.94 (0.84–1.05)	0.245
Year: 2021	1 [Reference]	–	1 [Reference]	–