Table 4.

Effects of demographic and clinical variables on vaccine breakthrough infection.

	Number of individuals	Number of COVID-19 infection at more than 14 days after the 2nd vaccination	Unadjusted Odds ratio for COVID-19 infection after vaccination (95% CI)	P value (Fisher’s exact test)	Adjusted odds ratio for COVID-19 infection after vaccination (95% CI)	P value (Multinomial logistic regression)
Age
<40 y	1859	388 (20.9%)	(reference)
≥40 y	855	184 (21.5%)	1.04 (0.853–1.267)	0.723	0.989 (0.808 – 1.21)	0.916
Sex
Male	1452	291 (20.0%)	(reference)
Female	1262	281 (22.3%)	1.143 (0.950–1.375)	0.157	1.127 (0.930 – 1.366)	0.222
BMI
<25 (non-obese)	1388	270 (19.5%)	(reference)
25–29.99 (obesity class I)	961	222 (23.1%)	1.244 (1.018–1.520)	0.035	0.816 (0.666 – 1.000)	0.050
≥30 (obesity class II)	359	79 (22.0%)	1.168 (0.880–1.550)	0.300	0.904 (0.677 – 1.207)	0.495
Smoking
No	2338	501 (21.4%)	(reference)
Yes	278	55 (19.8%)	0.904 (0.663–1.234)	0.587	1.032 (0.748 – 1.424)	0.847
Previous smoker	98	16 (16.3%)	0.715 (0.415 – 1.233)	0.257	1.340 (0.771 – 2.331)	0.300
Diabetes mellitus
No	2626	549 (20.9%)	(reference)
Yes	88	23 (26.1%)	1.339 (0.824–2.174)	0.233	1.269 (0.757 – 2.129)	0.366
Hypertension
No	2432	498 (20.5%)	(reference)
Yes	282	74 (26.2%)	1.382 (1.041–1.834)	0.031	1.369 (1.009 – 1.859)	0.044
CVD history
No	2672	565 (21.1%)	(reference)
Yes	42	7 (16.7%)	0.746 (0.330–1.688)	0.571	0.596 (0.253 – 1.402)	0.236
Lung disease/asthma history
No	2481	526 (21.2%)	(reference)
Yes	233	46 (19.7%)	0.914 (0.653–1.280)	0.674	0.890 (0.634 – 1.251)	0.503