Table 2.
Immunological parameters.
| Subjects and Immunological parameters | Unit | Before initial vaccination | 3 months after initial vaccination | Before booster dose | 1 month after booster dose | 1 month after versus before booster dose, p value | 3 months after booster dose | 3 months after versus before booster dose, p value |
|---|---|---|---|---|---|---|---|---|
| COVID-19 naive NH residents | ||||||||
| Anti-Spike antibodies | BAU/mL, median [IQR] | 0 [0;2·59] N = 51 |
529 [283;849] N = 51 |
87·4 [36·5;168·5] N = 46 |
2080 [2080;2080] N = 44 |
na* | 2080 [2080;2080] N = 43 |
na* |
| S1 specific reactive T cells | IFNg SFCs, median [IQR] | 1 [0;2] N = 51 |
13 [4·5;26·5] N = 49 |
10 [5;21] N = 46 |
19 [8·5;53] N = 45 |
0·0054 | 12·5 [5;27.5] N = 42 |
0·45 |
| Neutralizing antibodies against Delta | NT50, GMNT [95%CI] | na | na | 2·3 [1·3;4]** N = 43 |
na | 1825 [1150;2896] N = 43 |
<0·0001 | |
| Neutralizing antibodies against Omicron | NT50, GMNT [95%CI] | na | na | 1·2 [0·9;1·5]** N = 43 |
na | 37·3 [20·7;67·3] N = 43 |
<0·0001 | |
| COVID-19 recovered NH residents | ||||||||
| Anti-Spike antibodies | BAU/mL, median [IQR] | 141 [38·6;348] N = 64 | 2080 [1850;2080] N = 59 |
1900 [944;2080] N = 58 |
2080 [2080;2080] N = 57 |
na* | 2080 [1783;2080] N = 44 |
na* |
| S1 specific reactive T cells | IFNg SFCs, median [IQR] | 16·5 [8;33·7] N = 60 |
65 [23;153·3] N = 62 |
41 [17·5;102·5] N = 58 | 74 [17·5;102·5] N = 58 | 0·0019 | 52·5 [29·5;164·8] N = 44 |
<0·0001 |
| Neutralizing antibodies against Delta | NT50, GMNT [95%CI] | na | na | 235·4 [105·9;523·3] N = 42 |
na | 4200 [2593;6805] N = 42 |
<0·0001 | |
| Neutralizing antibodies against Omicron | NT50, GMNT [95%CI] | na | na | 8·3 [4·4;15·6]** N = 42 |
na | 101·4 [59·9;171·7] N = 42 |
<0·0001 | |
Data are median [IQR] or GMNT [95% CI] as indicated and N are number of samples available for each analysis. BAU/mL = binding antibody units (BAU)/mL. IQR=interquartile range. IFNg SFC = interferon gamma spot-forming cells/250 000 peripheral blood mononuclear cells. NT50 = neutralization titer. GMNT=geometric mean neutralization titer. 95%CI = 95% confidence interval. na: not available. N = are number of available samples for each analysis. * * no comparison was performed because a large part of antibody levels was greater than the upper limit of measure. ** Negative results (NT50 < 20) were set to 1 for statistical analyses.