Real-world vaccine effectiveness of mRNA vaccines for SARS-CoV-2; a test-negative case-control study in a medium-sized clinic

Figures & data

Table 1. Characteristics of participants during the periods of Delta variant predominance and Omicron variant surge.

Period of Delta variant predominance（N = 518）
Age, median (Q1; Q3):	44 （31, 56）
Gender (N):	Female 244, Male 274
SpO2 (%), median (Q1; Q3):	98 （97; 99）
Cases (N)	169 （32.6%）	Controls (N)	349 （67.6%）	P value
Age, median (Q1; Q3):	42 （30; 51）	Age, median (Q1; Q3):	44 （32; 59）	0.021
Female gender (%)	39.1	Female gender (%)	51	0.011
SpO2 (%), median (Q1; Q3):	98 （97; 99）	SpO2%), median (Q1; Q3):	98 （97; 99）	0.593
SpO2 <96% (N)	27 （5.21%%）	SpO2 < 96%	17 （3.3%）	<0.001
Unvaccinated (N)	138 （26.6%）	Unvaccinated (N)	138 （26.6%）	<0.001
Partially vaccinated (N)	12 （2.3%）	Partially vaccinated (N)	46 （8.9%）	0.052
Fully vaccinated (N)	19 （3.7%）	Fully vaccinated (N)	165 （31.9%）	<0.001
Period of Omicron variant surge（N = 358）
Age, median (Q1; Q3):	45 （35.25; 61）
Gender (N):	Female 167, Male191
SpO2 (%), median (Q1; Q3):	98 （97; 99）
Cases (N)	250 （69.8%）	Controls (N)	108 （30.2%）	P value
Age, median (Q1; Q3):	45.5 （36; 61.0）	Age, median (Q1; Q3):	44 （34; 60.3）	0.582
Female gender (%)	45.2	Female gender (%)	50	0.421
SpO2%), median (Q1; Q3):	98 （97; 99）	SpO2%), median (Q1; Q3):	98 （97; 99）	0.71
SpO2 < 96% (N)	5 （1.4%）	SpO2 < 96% (N)	2 （1.9%）	1
Unvaccinated	23 （6.4%）	Unvaccinated (N)	11 （3.1%）	0.845
Fully vaccinated	227 （63.4%）	Fully vaccinated (N)	97 （27.1%）	0.845

Q, quartile; P value, comparison between cases and controls.

Table 2. Vaccine effectiveness of the mRNA vaccines against SARS-CoV-2 during the period of Delta variant predominance.

	Vaccine	Vaccine status	Cases (vaccinated/ unvaccinated)	Controls (vaccinated/ unvaccinated)	Crude VE (%) (95% CI)	Adjusted VE^a (%) (95% CI)	P value
All COVID-19	BTN162b2	Full	14/138	109/138	87.1 (76.0 to 93.5)	89.6 (77.8 to 95.0)	<0.001
		Partial	10/138	26/138	61.4 (13.5 to 84.1)	62.1 (17.4 to 82.5)	0.015
	mRNA-1273	Full	5/138	44/138	88.6 (70.1 to 96.6)	89.0 (71.3 to 95.8)	<0.001
		Partial	1/138	11/138	90.9 (35.5 to 99.8)	90.6 (25.9 to 98.8)	<0.001
	Any mRNA vaccine	Full	19/138	165/138	89.0 (80.9 to 94.0)	90.4 (82.1 to 94.8)	<0.001
		Partial	138/138	46/138	71.7 (43.7 to 86.6)	75.0 (50.5 to 87.4)	<0.001
All COVID-19 age <65	Any mRNA vaccine	Full	9/130	107/132	91.4 (82.1 to 96.3)	87.7^b (55.2 to 96.6)	0.0015
All COVID-19 age ≥65	Any mRNA vaccine	Full	10/8	58/6	86.6 (45.7 to 96.9)	91.2^b (81.7 to 95.7)	<0.001
Moderate-to-severe COVID-19	BTN162b2	Full	2/21	14/6	99.6 (72.7 to 99.7)	99.8 (74.2 to 99.9)	0.0032
		Partial	2/21	2/6	70.0 (−394.5 to 98.2)	56.4 (−393 to 96.2)	0.502
	mRNA-1273	Full	2/21	2/6	69.9 (−251.4 to 99.7)	80.9 (−406 to 99.3)	0.322
		Partial	0/21	0/6	NA	NA	NA
	Any mRNA vaccine	Full	3/21	15/6	93.8 (68.5 to 99.1)	97.3 (71.7 to 99.7)	0.0025
		Partial	3/21	2/6	42.2 (−543.3 to 96.0)	41.1 (−469 to 94.0)	0.645
Moderate-to-severe COVID-19 age <65	Any mRNA vaccine	Full	0/16	4/5	NA	NA	NA
Moderate-to-severe COVID-19 age ≥65	Any mRNA vaccine	Full	3/5	11/1	93.4 (11.9 to 99.9)	94.4^b (31.0 to 99.5)	0.0246
All COVID-19 after recent history of close contact	Any mRNA vaccine	Full	7/52	16/20	82.8 (48.0 to 94.9)	90.6 (74.0 to 96.6)	<0.001

^aThe adjusted VE represents VE adjusted for age and gender using the logistic regression model; ^b the adjusted VE in the subgroup stratified for age was calculated for gender using the logistic regression model; CI, confidence interval; NA, not applicable.

Table 3. Vaccine effectiveness of the mRNA vaccines against SARS-CoV-2 during the period of Omicron variant surge.

	Vaccine	Vaccine status	Cases (vaccinated/unvaccinated)	Controls (vaccinated/unvaccinated)	Crude VE (%) (95% CI)	Adjusted VE^a (%) (95% CI)	P value
All COVID-19	Any mRNA vaccine	Full	227/23	97/11	10.6 (−111.4 to 60.0)	16.1 (−81.0 to 61.1)	0.653

^aThe adjusted VE represents VE adjusted for age and gender using the logistic regression model; CI, confidence interval.