SARS-CoV-2 reinfection and COVID-19 severity

Figures & data

Figure 1. Dynamic of SARS-CoV-2 infections and reinfections diagnosed at IHU Méditeranée Infection, 2020–2021.

Figure 2. Prevalence of reinfection (proportion of COVID patients who sustained a previous infection with SARS-CoV-2, red curve) and estimated risk for reinfection (proportion of patient infection during a given wave of COVID-19 who got reinfected at the time of study, histograms). The prevalence of reinfection increased from 0 to 1.54% from the first to the fourth wave. The risk for reinfection decreased from 0.77 for the first wave to 0.19 for the third wave (data were not available at the time the study was done to calculate the risk for reinfection for the fourth wave).

Table 1. Characteristics of the study population (N = 209).

	N = 209 (%)
Age (first infection)
Mean ± SD	40.4 ± 19.8
Range	1–94
<60	177 (84.7)
≥60	32 (15.3)
Gender
Female	108 (51.7)
Male	101 (48.3)
Comorbidities^N^= 177
At least one condition	68 (38.4)
Chronic respiratory disease	26 (14.7)
Chronic heart disease	23 (13.0)
Hypertension	20 (11.3)
Obesity	20 (11.3)
Diabetes	12 (6.8)
Immunosuppression	5 (2.8)
Vaccination status
Vaccination (first infection)^N^= 207	0 (0.0)
Vaccination (second infection)^N^= 202	13 (6.4)
One dose: 0/13 patients
Two doses: 13/13 patients
+ Interval between the last dose of vaccine and infection (days)
Mean ± SD	78.77 ± 49.77
Range	15–153
Antibody present (at second infection) ^N= 64	41 (62.1)
+4/5 vaccinated patients
+35/59 non-vaccinated patients
Interval between two infections (days)
Mean ± SD	232.93 ± 104.02
Range	90–513
≥180 days	130 (62.2)

Table 2. COVID-19 severity and SARS-CoV-2 variants in 209 reinfected patients.

	First infection N = 209 (%)	Second infection N = 209 (%)	p-value*
Hospitalization	19 (9.1%)	13 (6.2%)	0.23
ICU	5 (2.4%)	6 (2.9%)	0.74
Death	NA	2 (1.0%)	NA
Variant= 127/167
20A.EU2 (B.1.160)	48 (23.0%)	34 (16.3%)	<0.0001
20A (B.1)	25 (12.0%)	0 (0.0%)
20I (Alpha.V1) (B.1.1.7)	19 (9.1%)	25 (11.9%)
21A (Delta) (B.1.617.2)	0 (0.0%)	100 (47.9%)
20C (B.1)	11 (5.2%)	0 (0.0%)
Others^a	24 (11.5%)	8 (3.8%)
Not identified	82 (39.2%)	42 (20.1%)
Characteristics of patients with clinical information available
	n = 121	n = 121
Age (at first infection)
Mean ± SD	42.83 ± 19.13		–
Range	7–94		–
<60	103 (85.1)		–
≥60	18 (14.9)		–
Gender
Female	62 (51.2)		–
Male	59 (48.8)		–
Comorbidities
Chronic respiratory disease	20 (16.5)		–
Chronic heart disease	18 (14.9)		–
Hypertension	15 (12.4)		–
Obesity	14 (11.6)		–
Diabetes	10 (8.3)		–
Immunosuppression	5 (4.1)		–
Clinical symptoms
Fever	37 (30.6)	39 (32.2)	0.76
Cough	49 (40.5)	49 (40.5)	1.00
Sore throat	2 (1.7)	5 (4.1)	0.26
Rhinitis	23 (19.0)	17 (14.1)	0.18
Anosmia	26 (21.5)	18 (14.9)	0.19
Ageusia	23 (19.0)	17 (14.1)	0.33
Chest pain	16 (13.2)	12 (9.9)	0.39
Dyspnea	20 (16.5)	25 (20.7)	0.34
Asthenia	36 (29.8)	41 (33.9)	0.48
Headache	36 (29.8)	33 (27.3)	0.63
Myalgia	35 (28.9)	30 (24.8)	0.42
Nausea	1 (0.8)	2 (1.7)	0.56
Vomiting	2 (1.7)	3 (2.5)	0.65
Diarrhoea	22 (18.2)	12 (9.9)	0.03
Asymptomatic	28 (23.1)	35 (28.9)	0.32
COVID-19 severity
Hospitalization	13 (10.7)	12 (9.9)	0.76
ICU	5 (4.1)	6 (4.9)	0.74
Death	0 (0.0)	2 (1.7)	0.16

NA: not applicable.

^a 19A (B), 19B (A.19), 20A (B.1), 20A/S:98F (B.1.221), 20A (B.1.416.1), 20B (B.1.1), 20B (B.1.1.269), 20B (B.1.1.241), 20C/S:80Y (B.1.367), 20E (EU1) (B.1.177), 20H (Beta.V2) (B.1.351), 21D (Eta) (B.1.525).

*McNemar test.

Table 3. Risk factors for hospitalization among reinfected and primo-infected patients with 20I (Alpha.V1) (B.1.1.7), 20A.EU2 (B.1.160) and 21A (Delta) (B.1.617.2) (paired by age, gender, comorbidities, and variants of SARS-CoV-2) (N = 159).

Hospitalization N = 318	Univariate analysis	Multivariate analysis
	OR [95%CI] p-value	OR [95%CI] p-value
Primary infection	ref
Reinfection	0.79 [0.15–3.77] 0.74
Age (years)
<60	Ref	ref
≥60	18.6 [3.68–118.45] <0.0001	10.64 [2.01–56.32] 0.005
Gender
Female	Ref
Male	3.96 [0.74–39.49] 0.07
Comorbidities^N = 289
Hypertension
No	Ref
Yes	7.74 [1.14–39.59] 0.002
Diabetes
No	Ref
Yes	17.00 [2.27–96.48] <0.0001
Chronic respiratory disease
No	Ref
Yes	4.01 [0.61–19.82] 0.04
Chronic heart disease
No	Ref
Yes	12.23 [1.71–65.70] 0.0001
Obesity
No	Ref
Yes	5.43 [0.50–31.99] 0.03
Variant
20I (Alpha.V1) (B.1.1.7)	Ref
20A.EU2 (B.1.160)	3.06 [0.33–28.27] 0.32
21A (Delta) (B.1.617.2)	1.00 [0.11–9.15] 1.00