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. 2021 Sep 24;39(44):6520–6528. doi: 10.1016/j.vaccine.2021.09.052

Table 5.

Comparison of Antibody Titer in Different Vaccine Batches.



Antibody

Time Point

Parameter
 Batch

p-value**
Batch
20200308
(n = 131)		 Batch
20200412
(n = 134)		 Batch
20200419
(n = 132)
IgG (ELISA) V1 Seropositive rate n(%)
(95% CI)
14 (10.70)
(6.47–17.14)
16 (11.94)
(7.48–18.52)
14 (10.61)
(6.42–17.02)
0.927**)
GMT*)
(95% CI)
Median		 215.16
(205.70–225.05)
200.00		 223.40
(208.36–239.52)
200.00		 222.26
(209.08–236.27)
200.00		 0.384***)
V3 Seropositive rate n (%)
(95% CI)
Seroconversion n (%)
(95% CI)
GMT*)
(95% CI)
Median		 131 (1 0 0)
(97.15–100)
126 (96.18)
(92.38–98.36)
5093.78
(4369.78–5937.59)
5105.05		 133 (99.25)
(95.89–99.87)
131 (97.76)
(93.62–99.24)
5421.63
(4656.29–6312.77)
5787.62		 132 (1 0 0)
(97.17–100)
130 (98.48)
(94.64–99.58)
5032.34
(4314.30–5869.76)
5302.40		 0.374**)

0.476**)


0.898***)



Neutralization Antibody V1 Seropositive rate n(%)
(95% CI)		 0
(0–2.85)		 0
(0–2.94)		 0
(0–2.91)		 –
GMT*)
(95% CI)
Median		 2.00
–
–		 2.00
–
–		 2.00
–
–		 –
V3 Seropositive rate n (%)
(95% CI)
Seroconversion n (%)
(95% CI)
GMT*)
(95% CI)
Median		 126 (96.18)
(91.38–98.36)
118 (90.08)
(83.76–94.11)
15.97
(14.03–18.18)
16.00		 127 (94.78)
(89.61–97.45)
119 (88.81)
(82.35–93.10)
16.59
(14.47–19.02)
16.00		 127 (96.21)
(91.44–98.37)
109 (82.58)
(75.21–88.10)
14.75
(12.78–17.02)
16.00		 0.803**)

0.150**)

0.470***)

*) The comparison results after logarithmic transformation. **) Chi-square test; ***) ANOVA (F-test).

V1 = before injection.

V3 = 14 days after second injection.

IgG seropositive = titer > 200; seroconversion = four-fold increasing anti-RBD antibody IgG titer compare to baseline 14 days after the second dose.

Antibody neutralization seropositive = titer ≥ 1:4; seroconversion = a change from titer < 1:8 to titer ≥ 1:8; or a 4-fold increase from baseline titers if titer ≥ 1:8 14 days after the second dose.