Vaccination reduces viral load and accelerates viral clearance in SARS-CoV-2 Delta variant-infected patients

Figures & data

Figure 1. The flowchart of the study. NV, non-vaccination group; OV, one-dose vaccination; TV, two-dose vaccination.

Table 1. Baseline characteristics of patients in three groups.

	NV group (n = 31)	OV group (n = 21)	TV group (n = 60)	p value
Gender (M)	13 (42)	15 (71)	37 (62)	0.08
Age (years)	36.9 ± 13.8	22.5 ± 13.9	33.7 ± 13.7	0.001
BMI (Kg/ m^2)	22.7 ± 3.6	22.0 ± 5.8	23.2 ± 3.6	0.53
Comorbidities				0.32
Hypertension	2 (7)	0 (0)	1 (2)
Cirrhosis	2 (7)	0 (0)	1 (2)
Operation history	1 (3)	1 (5)	1 (2)
COPD	1 (3)	0 (0)	1 (2)
Type 2 diabetes	0 (0)	2 (10)	1 (2)
Any symptoms	31 (100)	16 (76)	33 (55)	<0.05
Stuffy nose/snot	1 (3)	1 (5)	1 (2)	0.74
Sore throat	4 (13)	1 (5)	3 (5)	0.35
Cough	14 (45)	7 (33)	20 (33)	0.52
Sputum production	8 (26)	4 (19)	5 (8)	0.08
Dyspnea	1 (3)	0 (0)	1 (2)	0.69
Intestinal symptom	3 (10)	0 (0)	0 (0)	0.02
Anosmia/dysgeusia	3 (10)	3 (14)	2 (3)	0.20
Fatigue	0 (0)	0 (0)	1 (2)	0.65

Data are presented as n (%) or mean ± standard deviation. NV: non-vaccines; OV: one-vacine; TV: two-vaccine; M: male; kg: kilogram; BMI: body mass index; COPD: chronic obstructive pulmonary disease. p value, comparison among groups.

Figure 2. Scatterplot of peak Ct values and time to peak of viral load among three groups. NV: non-vaccination group (black circle); OV: one-dose vaccination (green square); TV: two-dose vaccination (red triangle), the TV group showed the lower viral load and shorter time to peak than the NV and OV groups (p < 0.05).

Table 2. The clinical results of patients in three groups.

	NV group (n = 31)	OV group (n = 21)	TV group (n = 60)	p value
Contact history				0.43
Direct contact	28 (90)	19 (91)	49 (82)
Indirect contact	3 (10)	2 (10)	11 (18)
Clustered feature	25 (81)	16 (76)	42 (70)	0.54
CT positive	21 (68)	14 (67)	30 (50)	0.25
Classification				0.91
Mild	9 (29)	7 (33)	20 (33)
Common	22 (71)	14 (67)	40 (67)
Severe/critical	0 (0)	0 (0)	0 (0)
Cycle threshold	28.4 ± 5.7	29.4 ± 5.4	32.4 ± 5.1	<0.01
Time to peak (d)	4.8 ± 2.8	4.8 ± 2.9	3.5 ± 2.3	0.03
Antibody value
IgG (S/CO)	2.4 ± 3.2	4.7 ± 3.9	7.2 ± 3.3	<0.001
Ig M (S/CO)	3.2 ± 9.6	4.1 ± 13.9	7.6 ± 18.1	0.39
CRP positive	8 (26)	7 (33)	17 (28)	0.84

Data are presented as n (%) or mean ± standard deviation. NV: non-vaccines; OV: one-vacine; TV: two-vaccine; CRP: C reactive protein. p value, comparison among groups.

Table 3. The outcomes of patients in three groups.

	NV group (n = 31)	OV group (n = 21)	TV group (n = 60)	p value
Oxygen support	27 (87)	19 (91)	58 (97)	0.22
No-drug used	4 (13)	2 (10)	11 (18)	<0.001
Anticoagulation	16 (52)	11 (52)	36 (60)	0.69
Antibodies/convalescent plasma	0 (0)	0 (0)	0 (0)	NA
Thymalfasin	2 (7)	2 (10)	4 (7)	0.89
Lopinavir/ritonavir	0 (0)	0 (0)	1 (2)	0.65
Hospital stay (d)	17.6 ± 4.4	17.1 ± 3.5	14.4 ± 2.2	<0.01
Viral clearance time (d)	14.3 ± 3.6	13.8 ± 3.6	11.2 ± 1.9	<0.001
Time to peak (d)	4.8 ± 2.8	4.8 ± 2.9	3.5 ± 2.2	0.03
Symptom recovery
Stuffy nose/snot	0 (0)	0 (0)	0 (0)	NA
Sore throat	0 (0)	0 (0)	0 (0)	NA
Cough	0 (0)	0 (0)	0 (0)	NA
Sputum production	0 (0)	0 (0)	0 (0)	NA
Dyspnea	0 (0)	0 (0)	0 (0)	NA
Intestinal symptom	0 (0)	0 (0)	0 (0)	NA
Anosmia/dysgeusia	1 (3)	1 (5)	1 (2)	0.74
Fatigue	0 (0)	0 (0)	0 (0)	NA
Death/ARDS	0 (0)	0 (0)	0 (0)	NA
MI/Stroke	0 (0)	0 (0)	0 (0)	NA
DVT	0 (0)	0 (0)	0 (0)	NA

Data are presented as n (%) or mean ± standard deviation. NV: non-vaccines; OV: one-vacine; TV: two-vaccine; ARDS: acute respiratory distress syndrome; MI: myocardial infarction; DVT: deep vein thrombosis. p value, comparison among groups.

Data availability statement

The datasets used and analyzed during this study are available from the corresponding author upon reasonable request. We confirmed that these patients have not been reported in any other submission by all authors or anyone else.