Volume 13, Number 10—October 2007
Dispatch
Duration of Antibody Responses after Severe Acute Respiratory Syndrome
Table
Cumulative rates of SARS-CoV antibodies among 176 SARS patients with known transmission histories*
Time after symptom onset, d | IgG |
IgM† |
|||||
---|---|---|---|---|---|---|---|
No. samples tested | No. positive samples (%) | Average OD | No. samples tested | No. positive samples (%) | Average OD | ||
0–7 | 17 | 2 (11.76) | 0.046 | 14 | 3 (21.43) | 0.136 | |
8–14 | 26 | 10 (38.46) | 0.190 | 22 | 14 (63.64) | 0.312 | |
15–20 | 22 | 17 (77.27) | 0.351 | 19 | 12 (63.16) | 0.477 | |
21–30 | 36 | 33 (91.67) | 0.493 | 21 | 16 (76.19) | 0.560 | |
31–60 | 72 | 67 (93.06) | 0.627 | 22 | 14 (63.64) | 0.320 | |
61–90 | 35 | 33 (94.29) | 0.745 | 15 | 5 (33.33) | 0.167 | |
91–120 | 11 | 11 (100.00) | 0.965 | ND | ND | ND | |
121–210 | 23 | 23 (100.00) | 0.932 | ND | ND | ND | |
211–365 | 49 | 46 (93.88) | 0.734 | ND | ND | ND | |
366–763 | 96 | 86 (89.58) | 0.535 | ND | ND | ND | |
764–1,265 | 28 | 15 (53.57) | 0.250 | ND | ND | ND |
*SARS-CoV, severe acute respiratory syndrome–associated coronavirus; Ig, immunoglobulin; OD, optical density; ND, not determined because for most samples the IgM readings already reached background level on day 90.
†For some patients, we did not have enough serum to test for IgM after testing for IgG; hence, a smaller number of serum samples were tested for IgM than for IgG.