Table 2 Outputs from generalized additive models, with immune marker values associated with 50%, 60%, 70%, 80%, and 90% VE against symptomatic infection

From: Correlates of protection against symptomatic and asymptomatic SARS-CoV-2 infection

Assay units

P value immune marker

P value baseline risk score

No. cases

No. noncase

50% VE (95% CI)

60% VE (95% CI)

70% VE (95% CI)

80% VE (95% CI)

90% VE (95% CI)

Anti-spike IgG

AU/ml

0.003

<0.001

52

1155

4446 (NC, 12822)

8413 (NC, 22232)

17538 (NC, 37929)

40923 (16748, 125017)

139306 (57276, NC)

BAU/ml

    

29 (NC, 83)

54 (NC, 143)

113 (NC, 245)

264 (108, 806)

899 (369, NC)

Anti-RBD IgG

AU/ml

0.018

<0.001

52

1155

2193 (NC, 13614)

6266 (NC, 29105)

20700 (NC, 56620)

63383 (16903, NC)

295781 (90567, NC)

BAU/ml

    

17 (NC, 109)

50 (NC, 232)

165 (NC, 452)

506 (135, NC)

2360 (723, NC)

Normalized live-virus neutralization assay

NF50

<0.001

<0.001

36

412

68 (NC, 129)

91 (NC, 175)

135 (48, 267)

247 (101, NC)

938 (294, NC)

Pseudovirus neutralization assay

ID50

0.005

<0.001

47

828

NC

22 (NC, 76)

57 (NC, 183)

185 (NC, NC)

982 (303, NC)

IU/ml

    

NC

3 (NC, 11)

8 (NC, 26)

26 (NC, NC)

140 (43, NC)

  1. ID50: neutralization dilution for 50% virus inhibition; NC: not computed; AU/ml: arbitrary units per mL; BAU/ml: binding antibody units per ml (WHO international standard 20/136), IU/ml: international units per ml (WHO international standard 20/136).
  2. Where CIs were outside the range of values of the assay the limits are reported as NC. VE estimates and CIs are those shown in Fig. 4, at every 10% increment in the y axis. The two-sided P value for each immune marker (column 2) is from the generalized additive models in Fig. 1, showing the strength of the relationship between the antibody value and infection. The P values were not adjusted for multiple comparisons.