TABLE 2.
Antibody responses to CRPV VLP-L1 detected by ELISA
| Vaccination strategy | Vaccinea
|
Rabbit no. | ELISA VLP-L1 antibody titer (relative to time of immunization)d
|
Level of protection (%)e | ||
|---|---|---|---|---|---|---|
| Primary (PFU, 5 × 105) | Booster (PFU, 1 × 107) | wk 7-8 | wk 10-13 | |||
| Expt 1 | VSV-L1 (i.n.)b | 6 | >1:12,800 | 1:6,400 | 100.0 | |
| 7c | — | — | 79.3 | |||
| 8 | >1:12,800 | 1:6,400 | 100.0 | |||
| 9 | — | — | 0.0 | |||
| 10 | 1:6,400 | 1:3,200 | 98.3 | |||
| Expt 2 | VSV-L1 (i.d.) | VSV-L1 (i.d.) | 1 | 1:6,400 | >1:12,800 | 100.0 |
| 2 | >1:12,800 | >1:12,800 | 99.4 | |||
| 3 | 1:1,600 | 1:6,400 | 100.0 | |||
| VSV-L1 (i.n.) | VSV-L1 (i.n.) | 4 | — | 1:6,400 | 100.0 | |
| 5 | — | 1:3,200 | 100.0 | |||
| 6 | >1:12,800 | >1:12,800 | 100.0 | |||
| VSV-L1 (i.m.) | VSV-L1 (i.m.) | 7 | 1:3,200 | 1:3,200 | 100.0 | |
| 8 | 1:3,200 | >1:12,800 | 100.0 | |||
| 9 | >1:12,800 | >1:12,800 | 100.0 | |||
| VSV-L1 (i.vag.) | 10 | — | — | NA | ||
| 11 | — | — | NA | |||
| 12 | — | — | NA | |||
a
All rabbits in this group were given 10 μg of denatured L1 protein intradermally at 7 weeks postvaccination.
b
i.n., intranasal; i.d., intradermal; i.m., intramuscular; i.vag., intravaginal.
c
Rabbit was administered a boost of VSV-L1 at 5 weeks due to failure of the primary vaccination.
d
—, VLP-L1 titer < 1:100. Postboost neutralization titers are in boldface. Preimmunization titers were all <1:100.
e
Determined by the formula [1 − (total papilloma volume of vaccinated rabbit/average papilloma volume of control rabbits)] × 100. NA, not applicable.