Table 2. Geometric Mean Humoral Immunogenicity Assay Responses to mRNA-1273 in Participants and in Convalescent Serum Specimens.*.
| Time Point | 25-μg Group | 100-μg Group | 250-μg Group | Convalescent Serum | ||||
|---|---|---|---|---|---|---|---|---|
| no. | GMT (95% CI) | no. | GMT (95% CI) | no. | GMT (95% CI) | no. | GMT (95% CI) | |
| ELISA anti–S-2P | 38 | 142,140 (81,543–247,768) |
||||||
| Day 1 | 15 | 116 (72–187) |
15 | 131 (65–266) |
15 | 178 (81–392) |
||
| Day 15† | 15 | 32,261 (18,723–55,587) |
15 | 86,291 (56,403–132,016) |
15 | 163,449 (102,155–261,520) |
||
| Day 29 | 15 | 40,227 (29,094–55,621) |
15 | 109,209 (79,050–150,874) |
14 | 213,526 (128,832–353,896) |
||
| Day 36 | 13 | 391,018 (267,402–571,780) |
15 | 781,399 (606,247–1,007,156) |
14 | 1,261,975 (973,972–1,635,140) |
||
| Day 43 | 13 | 379,764 (281,597–512,152) |
14 | 811,119 (656,336–1,002,404) |
14 | 994,629 (806,189–1,227,115) |
||
| Day 57 | 13 | 299,751 (206,071–436,020) |
14 | 782,719 (619,310–989,244) |
13 | 1,192,154 (924,878–1,536,669) |
||
| ELISA anti–receptor-binding domain | 38 | 37,857 (19,528–73,391) |
||||||
| Day 1 | 15 | 55 (44–70) |
15 | 166 (82–337) |
15 | 576 (349–949) |
||
| Day 15† | 15 | 6567 (3651–11,812) |
15 | 34,073 (21,688–53,531) |
15 | 87,480 (51,868–147,544) |
||
| Day 29 | 15 | 18,149 (11,091–29699) |
15 | 93,231 (59,895–145,123) |
14 | 120,088 (71,013–203,077) |
||
| Day 36 | 13 | 208,652 (142,803–304,864) |
15 | 499,539 (400,950–622,369) |
14 | 720,907 (591,860–878,090) |
||
| Day 43 | 13 | 233,264 (164,756–330,259) |
14 | 558,905 (462,907–674,810) |
14 | 644,395 (495,808–837,510) |
||
| Day 57 | 13 | 183,652 (122,763–274,741) |
14 | 371,271 (266,721–516,804) |
13 | 582,259 (404,019–839,134) |
||
| GMR (95% CI) | GMR (95% CI) | GMR (95% CI) | GMR (95% CI) | |||||
| PsVNA ID50‡ | 38 | 109.2 (59.6–199.9) |
||||||
| Day 1 | 15 | 10 | 15 | 10 | 15 | 10 | ||
| Day 15† | 15 | 14.5 (9.8–21.4) |
15 | 23.7 (13.3–42.3) |
15 | 26.1 (14.1–48.3) |
||
| Day 29 | 15 | 11.7 (9.7–14.1) |
15 | 18.2 (12.1–27.4) |
14 | 20.7 (13.3–32.2) |
||
| Day 36 | 13 | 105.8 (69.8–160.4) |
15 | 256.3 (182.0–361.1) |
14 | 373.5 (308.6–452.2) |
||
| Day 43 | 13 | 112.3 (71.2–177.1) |
14 | 343.8 (261.2–452.7) |
14 | 332.2 (266.3–414.5) |
||
| Day 57 | 13 | 80.7 (51.0–127.6) |
14 | 231.8 (163.2–329.3) |
14 | 270.2 (221.0–330.3) |
||
| Live virus PRNT80 | 3 | 158.3 (15.1–1663.0) |
||||||
| Day 1§ | 15 | 4 | 15 | 4 | NA | |||
| Day 43 | 13 | 339.7 (184.0–627.1) |
14 | 654.3 (460.1–930.5) |
NA | |||
*
ELISA denotes enzyme-linked immunosorbent assay, GMT geometric mean titer, GMR geometric mean response, ID50 50% inhibitory dilution, NA not available, PRNT80 plaque-reduction neutralization testing assay that shows reduction in SARS-CoV-2 infectivity by 80% or more, and PsVNA pseudotyped lentivirus reporter neutralization assay.
†
Seroconversion occurred in all participants at day 15.
‡
Samples that did not neutralize at the 50% level are expressed as less than 20 and plotted at half that dilution (i.e., 10).
§
All day 1 specimens exhibited less than 80% inhibitory activity at the lowest dilution tested (1:8) and were assigned a titer of 4.