Table 2. ELISA titers to the indicated antigens.
| Group | Immunogen | MPER titer* (s.e.m.) | T20 titer* (s.e.m.) | Immunogen titer* (s.e.m.) | MPER/Immu-nogen titer (%) |
|---|---|---|---|---|---|
| S2 | FDA18 | 3695** (689) | 8095 (1754) | 74,379 (837) | 5.0 |
| S1 | FDA13 | 3065** (1029) | 7605 (1519) | 60,404 (1362) | 5.1 |
| S3 | FDA20 | 460 (74) | 3058 (296) | 56,204 (2462) | 0.8 |
| S6 | FDA26 | 5213** (801) | 6818 (1326) | 39,579 (4137) | 13.2 |
| S4 | FDA21 | 990** (176) | 3533 (776) | 45,504 (2538) | 2.2 |
| S7 | FDAB4 | 80 (13) | 740 (166) | 63,029 (537) | 0.1 |
| S5 | FDA22 | 318 (18) | 1780 (995) | 81,754 (4162) | 0.4 |
| H1 | FDA13, 18, 22 *** | 2364** (66) | 5415 (1194) | 59321 (2046) | 4.0 |
* titer = mean ELISA units (EU, endpoint dilution x O.D. 450nm) from two independent assays. (s.e.m.) = standard error of mean
**Indicates significantly higher than FDAB4 by one-sided t test.
*** Two rabbits each were immunized with two doses each of the indicated antigens given in various order as described in Materials and Methods.