Effectiveness of COVID-19 vaccine (Covaxin) against breakthrough SARS-CoV-2 infection in India

Figures & data

Figure 1. The flow diagram of study participants selection, data collection and analysis.

Table 1. Characteristics of study participants (n = 670)

	Control (n = 335)	Case (n = 335)	Total (n = 670)	P-value
Mean age in years (Mean ± SD)	29.2 ± 7.2	28.9 ± 7.1	29.1 ± 7.1	.647
Age groups (in years)
<30	205 (61.19)	203 (60.60)	408 (60.90)	.797
30–39	98 (29.25)	106 (31.64)	204 (30.45)
40–49	22 (6.57)	17 (5.07)	39 (5.82)
≥50	10 (2.99)	9 (2.69)	19 (2.84)
Gender
Male	184 (54.93)	186 (55.52)	370 (55.22)	.877
Female	151 (45.07)	149 (44.48)	300 (44.78)
Type of household
Extended family	8 (2.39)	15 (4.48)	23 (3.43)	.273
Nuclear family	169 (50.45)	152 (45.37)	321 (47.91)
With friend or roommate	56 (16.72)	53 (15.82)	109 (16.27)
Living alone	102 (30.45)	115 (34.33)	217 (32.39)
Profession
Nursing staff	122 (36.42)	122 (36.42)	244 (36.42)	1.000
Supporting staff	98 (29.5)	98 (29.5)	196 (29.25)
Doctors	49 (14.63)	49 (14.63)	98 (14.63)
Students	38 (11.34)	38 (11.34)	76 (11.34)
Others*	24 (7.16)	24 (7.16)	48 (7.16)
Administrative staff	4 (1.19)	4 (1.19)	8 (1.19)
Do you have symptoms** suggestive of COVID-19 at the time of diagnosis?
Yes	117 (34.93)	258 (77.01)	375 (55.97)	.000
No	218 (65.07)	77 (22.99)	295 (44.03)
Whether you are involved in direct patient care***?
Yes	171 (51.04)	171 (51.04)	342 (51.04)	1.000
No	164 (48.96)	164 (48.96)	328 (48.96)
Do you have ****past h/o of COVID-19 disease?
Yes	31 (9.25)	21 (6.27)	52 (7.76)	.149
No	304 (90.75)	314 (93.73)	618 (92.24)
Vaccination status
Completely immunized	208 (62.09)	194 (57.91)	402 (60.00)	.468
Partial immunized	61 (18.21)	63 (18.81)	124 (18.51)
Not immunized	66 (19.70)	78 (23.28)	144 (21.49)

*Other profession includes Electrical engineer, audiologist, cashier, clerk, cook, CSSD helper, data entry operator, Dietician, fire safety department staff, health educator, lab technician, lift technician, plumber, psychologist, pump operator and swasthya Mitra.

**Symptoms for COVID-19 as per WHO guideline (https://www.who.int/health-topics/coronavirus#tab=tab_3).

***doctors and nurses were involved direct patient care.

****Within last 12 months.

Table 2. Profile of the COVID-19 cases (n = 335)

Variables	Number of participants (n = 335)	%
COVID-19 disease
Mild	330	98.5
Moderate	5	1.5
Severe	0	0
Type of isolation opted
Home Isolation	320	95.5
Institutional Isolation	9	2.7
Admitted to hospital	6	1.8
Testing reason
Symptoms suggestive of COVID-19	257	76.7
High risk contact*	49	14.6
Traveling purpose	21	6.3
Others**	8	2.4
Types of contact
Workplace	74	22.1
Social	22	6.6
Home	11	3.3
Contact h/o cannot be identified	228	68.0

*High risk contact (https://aiimsbhubaneswar.nic.in/writereaddata/upload/Documents/COVID.pdf).

**Other for a reason for testing COVID-19 RT-PCR includes-as a requirement for undergoing a surgical procedure and joining the institute.

Table 3. Conditional logistic regression models for associated factors of SARS-CoV-2 infection (n = 670)

Variable	Unadjusted odds ratio (95% CI)	p-value	Model-1		Model-2		Model-3
			Adjusted odds ratio (95% CI)	p-value	Adjusted odds ratio (95% CI)	p-value	Adjusted odds ratio (95% CI)	p-value
Age groups (in years)
<30	Reference		Reference		Reference		Reference
30–39	1.10 (0.65–1.88)	.719	1.07 (0.61–1.86)	.809	1.06 (0.61–1.85)	.836	1.08 (0.61–1.89)	.782
40–49	0.53 (0.17–1.69)	.285	0.46 (0.14–1.52)	.204	0.44 (0.13–1.44)	.173	0.44 (0.13–1.45)	.176
≥50	0.59 (0.11–3.08)	.534	0.49 (0.09–2.64)	.407	0.51 (0.09–2.72)	.428	0.58 (0.11–3.13)	.522
Gender
Male	Reference		Reference		Reference		Reference
Female	0.95 (0.64–1.44)	.837	0.96 (0.63–1.45)	.833	0.94 (0.62–1.43)	.776	0.94 (0.61–1.43)	.779
Type of household
Extended family	Reference		Reference		Reference		Reference
Nuclear family	0.45 (0.18–1.09)	.079	0.42 (0.17–1.03)	.058	0.41 (0.17–1.01)	.052	0.43 (0.17–1.08)	.072
With friend or roommate	0.49 (0.19–1.26)	.137	0.45 (0.17–1.17)	.101	0.44 (0.16–1.15)	.094	0.47 (0.18–1.27)	.136
Living alone (either hostels or outside)	0.69 (0.28–1.72)	.429	0.65 (0.26–1.63)	.358	0.62 (0.25–1.58)	.322	0.69 (0.27–1.75)	.431
Do you have past h/o of COVID-19 disease*?
No	Reference				Reference		Reference
Yes	0.66 (0.37–1.17)	.152			0.63 (0.35–1.15)	.133	0.64 (0.35–1.15)	.135
Vaccination status
Not immunized	Reference						Reference
Partial immunized	0.87 (0.53–1.42)	.577					0.88 (0.53–1.46)	.631
Completely immunized	0.79 (0.53–1.15)	.220					0.78 (0.52–1.17)	.233

*The h/o of COVID-19 disease within last 12 months was considered.

Table 4. Conditional logistic regression models for associated factors of SARS-CoV-2 infection for COVAXIN vaccination (n = 624)

Variable	Unadjusted odds ratio (95% CI)	p-value	Model-1		Model-2		Model-3
			Adjusted odds ratio (95% CI)	p-value	Adjusted odds ratio (95% CI)	p-value	Adjusted odds ratio (95% CI)	p-value
Age groups (in years)
<30	Reference		Reference		Reference		Reference
30–39	1.22 (0.70–2.13)	.492	1.19 (0.67–2.13)	.553	1.17 (0.65–2.10)	.596	1.22 (0.68–2.20)	.508
40–49	0.58 (0.17–1.93)	.372	0.48 (0.14–1.67)	.247	0.45 (0.12–1.56)	.206	0.44 (0.12–1.57)	.208
≥50	0.40 (0.06–2.60)	.335	0.29 (0.04–1.97)	.207	0.31 (0.05–2.05)	.222	0.35 (0.05–2.35)	.280
Gender
Male	Reference		Reference		Reference		Reference
Female	0.98 (0.64–1.49)	.914	0.99 (0.64–1.55)	.982	0.98 (0.63–1.52)	.936	0.98 (0.62–1.53)	.917
Type of household
Extended family	Reference		Reference		Reference		Reference
Nuclear family	0.34 (0.13–0.89)	.028	0.30 (0.11–0.80)	.017	0.29 (0.11–0.80)	.016	0.31 (0.11–0.85)	.023
With friend or roommate	0.35 (0.12–1.01)	.051	0.31 (0.11–0.91)	.034	0.31 (0.10–0.91)	.033	0.33 (0.11–1.00)	.050
Living alone (either hostels or outside)	0.54 (0.20–1.48)	.231	0.49 (0.18–1.36)	.170	0.48 (0.17–1.34)	.160	0.53 (0.19–1.50)	.231
Do you have past h/o of COVID-19 disease*?
No	Reference				Reference		Reference
Yes	0.61 (0.33–1.11)	.105			0.60 (.32–1.12)	.108	0.60 (0.33–1.12)	.112
Vaccination status
Not Immunized	Reference						Reference
Partial immunized	0.82 (0.50–1.37)	.450					0.82 (0.49–1.39)	.470
Completely immunized	0.72 (0.48–1.08)	.116					0.71 (0.47–1.08)	.114

*The h/o of COVID-19 disease within last 12 months was considered.