TABLE 2.
CMV neutralization by serum from mice immunized with VRP expressing CMV gB
| VRP vaccine | CMV neutralization titer (mean ± SEM)a
|
||
|---|---|---|---|
| Day −1 | Day 28 | Day 63 | |
| gB | <40 | 93 ± 13 | 400 ± 107 |
| TrgB | <40 | 253 ± 43b | 553 ± 67c |
| pp65+gB dp | <40 | 73 ± 7 | 240 ± 36 |
| pp65+IE1+gB tp | <40 | 60 ± 9 | 200 ± 40c |
| pp65+IE1+TrgB tp | <40 | 140 ± 41 | 373 ± 89 |
| pp65/IE1 fusion+TrgB dp | <40 | 133 ± 17 | 267 ± 79 |
Mice (six per group) were immunized with the indicated vaccines at days 0, 21, and 56, and serum was obtained on days 28 and 63. The neutralization titer is the reciprocal of the serum dilution that resulted in a 50% reduction in CMV infectivity. VRP designations are as in Table 1. The titers in this assay were 320 and 640 for serum samples from two CMV-seropositive humans.
At day 28, the antibody response in the group immunized with TrgB VRP was significantly different (P < 0.05) from those of all other groups, but other differences between the groups were not statistically significant.
At day 63, the antibody response in groups immunized with TrgB VRP or pp65+IE1+gB tp VRP were significantly different (P < 0.05) from one another, but other differences between the groups were not statistically significant.