Table 3 Positive-responder rates of mutant SP/RBD IgG titers at day 28 of AKS-452 vaccination

From: Immunogenicity phase II study evaluating booster capacity of nonadjuvanted AKS-452 SARS-Cov-2 RBD Fc vaccine

Positive respondersa within

 

100% of subjects (N = 67) b

lower 87% of subjects ranked by day-0 titers (N = 58) b

upper 13% of subjects ranked by day-0 titers (N = 9) b

87%/13% day-0 cut-off titer (ug/mL) c

SP/RBD variant

N

% of N = 67

N

% of N = 58

mean SI (SEM)

Max SI

N

% of N = 9

mean SI (SEM)

Max SI

WT (ACRO)

45

67%

44

76%

21.9 (9.7)

420

1

11%

2.6 (n/a)

2.6

150

Delta (L452R, T478K)

40

60%

37

64%

22.1 (10.7)

397

3

33%

3.9 (1.4)

6.7

190

Beta (K417N, E484K, N501Y)

42

63%

39

67%

29.7 (16.3)

636

3

33%

3.8 (1.6)

7.1

113

Omicron B.1.1.529

45

67%

43

74%

30.2 (15.0)

637

3

33%

4.1 (2.1)

8.4

99

Omicron BA.2

44

66%

41

71%

25.9 (12.3)

494

3

33%

4.2 (1.4)

7.0

99

Omicron (BA.2.75)

46

69%

44

76%

18.7 (6.0)

225

4

44%

3.3 (0.5)

4.7

115

Omicron (BA.2.12.1)

46

69%

42

72%

25.4 (13.2)

553

4

44%

4.7 (1.7)

5.9

100

Omicron (BA.3)

44

66%

40

69%

24.5 (11.7)

464

4

44%

4.0 (1.5)

8.3

112

Omicron (BA.4&BA.5)

47

70%

45

78%

29.3 (16.9)

759

3

33%

4.2 (2.4)

9.0

95

  1. aA “positive responder” subject was defined as having > 2-fold change in anti-SP/RBD IgG titer from day-0 to day-28 after a single 90 µg AKS-452 vaccination dose.
  2. bDay-0 mean IgG titers from all 67 subjects per mutant SP/RBD ELISA were rank ordered and grouped by the lower 87% (i.e., 58 subjects) and the upper 13% (i.e., 9 subjects) and positive responder rates, mean ± SEM of the fold-change in titer (stimulation index, SI), and the Maximum SI of the positive responders were determined.
  3. cThe IgG titer of the subject defining the cut-off between the lower 87% and the upper 13% of the rank ordered titers.
Back to article page