Table 2.

Vaccine Effectiveness by Dose against Severe COVID-19.

		Severe COVID-19
	Number of vaccinations	Patients	Vaccine effectiveness*
		n/total (%)	percent (95% CI)
All	0	54/34,097 (0.2%)	Reference
	1	2/705 (0.3%)	−3.5% [−301.7-73.4]
	2	37/30,134 (0.1%)	55.5% [32.6-71.7]
	3	57/25,540 (0.2%)	76.9% [66.7-84.0]
	4	19/2,174 (0.9%)	75.7% [58.8-85.7]
Over 65	0	50/953 (5.3%)	Reference
	1	2/37 (5.4%)	−4.6% [−308.0-73.2]
	2	35/1,418 (2.5%)	52.5% [27.2-69.0]
	3	54/4,391 (1.2%)	77.0% [66.4-84.2]
	4	19/1,414 (1.3%)	76.5% [60.1-86.2]

*Adjusted for age, sex, comorbidities, obesity, pregnancy, and smoking status. CI: confidence interval