Table 1. Participant characteristics according to primary vaccine regimen (N = 285).
| Total | (BNT162b2 x 2) + BNT162b2 | (BBIBP-CorV x 2) + BNT162b2 | p-value* | |
|---|---|---|---|---|
| N = 285 | N = 56 | N = 229 | ||
| n (%) | Median [IQR] | n (%) | Median [IQR] | n (%) | Median [IQR] | ||
| Age (years) | 46 [36; 60] | 67 [62; 73] | 43 [34; 53] | <0.001‡ |
| Age Group | ||||
| 18–29 years old | 23 (8.1) | 0 (0.0) | 23 (10.0) | <0.001†† |
| 30–59 years old | 189 (66.3) | 6 (10.7) | 183 (79.9) | |
| 60 plus years old | 73 (25.6) | 50 (89.3) | 23 (10.0) | |
| Gender | ||||
| Female | 190 (66.7) | 28 (50.0) | 162 (70.7) | 0.003† |
| Male | 95 (33.3) | 28 (50.0) | 67 (29.3) | |
| Comorbidity | ||||
| No Comorbidities | 214 (75.1) | 28 (50.0) | 186 (81.2) | <0.001† |
| Presence of Comorbidities | 71 (24.9) | 28 (50.0) | 43 (18.8) | |
| Number of Comorbidities | ||||
| No Comorbidities | 214 (75.1) | 28 (50.0) | 186 (81.2) | <0.001† |
| One Comorbidity | 61 (21.4) | 22 (39.3) | 39 (17.0) | |
| Two or more Comorbidities | 10 (3.5) | 6 (10.7) | 4 (1.8) | |
| List of Comorbidities | ||||
| High Blood pressure | 29 (10.2) | 15 (26.8) | 14 (6.1) | <0.001† |
| Diabetes Mellitus | 17 (6.0) | 8 (14.3) | 9 (3.9) | 0.003† |
| Obesity | 7 (2.5) | 0 (0.0) | 7 (3.1) | 0.352†† |
| Asthma/COPD | 12 (4.2) | 2 (3.6) | 10 (4.4) | 1.000†† |
| Cancer (any type) | 5 (1.8) | 3 (5.4) | 2 (0.9) | 0.054†† |
| Cardiovascular Disease | 2 (0.7) | 0 (0.0) | 2 (0.9) | 1.000†† |
| Others | 12 (4.2) | 7 (12.5) | 5 (2.2) | 0.001† |
| Prior COVID-19 Infection | ||||
| No | 201 (70.5) | 45 (80.4) | 156 (68.1) | 0.072† |
| Yes | 84 (29.5) | 11 (19.6) | 73 (31.9) | |
| Time until booster dose (months) | ||||
| 5 | 33 (11.6) | 33 (58.9) | 0 (0.0) | <0.001†† |
| 6 | 78 (27.4) | 20 (35.7) | 58 (25.3) | |
| 7 | 159 (55.8) | 3 (5.4) | 156 (68.1) | |
| 8 | 15 (5.3) | 0 (0.0) | 15 (6.6) | |
| Adverse Reactions after booster | ||||
| No | 34 (11.9) | 13 (23.2) | 21 (9.2) | 0.004† |
| Yes | 251 (88.1) | 43 (76.8) | 208 (90.8) | |
| Number of Adverse Reactions | ||||
| None | 34 (11.9) | 13 (23.2) | 21 (9.2) | <0.001† |
| One | 104 (36.5) | 26 (46.4) | 78 (34.1) | |
| Two or more | 147 (51.6) | 17 (30.4) | 130 (56.8) | |
| Adverse Reaction occurred | ||||
| Local pain | 242 (84.9) | 43 (76.8) | 199 (86.9) | 0.058† |
| Malaise | 93 (32.6) | 11 (19.6) | 82 (35.8) | 0.021† |
| Headache | 79 (27.7) | 6 (10.7) | 73 (31.9) | 0.002† |
| Drowsiness | 43 (15.1) | 3 (5.4) | 40 (17.5) | 0.022†† |
| Fever | 41 (14.4) | 6 (10.7) | 35 (15.3) | 0.382† |
| Others | 54 (19.0) | 1 (1.8) | 53 (23.1) | <0.001†† |
| Time between 1st and 2nd sample (days) | 15 [14; 15] | 14 [14; 17] | 15 [14; 15] | 0.686‡ |
IQR: Interquartile range. IgG: Immunoglobulin G. AU/ml: Arbitrary units per ml.
†Chi Square test.
††Fisher´s Exact test.
‡Mann-Whitney U test.
*Comparison between BNT162b2 x 2 + BNT162b2 vs BBIBP-CorV x 2 + BNT162b2.