TABLE 1.
Serum antibody activity in pre- and postvaccination sera from MeNZB and MenBvac vaccinees measured in four antibody assays with the two vaccine strainsa
| Target strain | Vaccineb | IgG titer by ELISAc (kAU/ml)
|
Pd | IgG titer by flow cytometryc (AU/ml)
|
Pd | SBA assay resultc (titer)
|
Pd | OPA assay resultc (titer)
|
Pd | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prevaccination sera | Postvaccination sera | Prevaccination sera | Postvaccination sera | Prevaccination sera | Postvaccination sera | Prevaccination sera | Postvaccination sera | ||||||
| NZ98/254 (vaccine strain for MeNZB) | MeNZB | 20 (0-244) | 456 (164-660) | <0.001 | 3 (1-28) | 47 (8-895) | NS | 1 (1-32) | 26 (1-416) | 0.038 | 1 (1-32) | 48 (4-256) | NS |
| MenBvac | 20 (0-300) | 252 (24-584) | 2 (1-83) | 53 (5-1,980) | 1 (1-111) | 16 (1-239) | 1 (1-64) | 32 (1-1,024) | |||||
| 44/76-SL (vaccine strain for MenBvac) | MeNZB | 40 (0-264) | 268 (92-568) | <0.001 | 8 (1-147) | 41 (1-712) | NS | 1 (1-28) | 6 (1-169) | NS | 1 (1-32) | 16 (1-128) | NS |
| MenBvac | 28 (0-300) | 448 (184-624) | 2 (1-468) | 125 (6-2,875) | 1 (1-104) | 11 (1-478) | 1 (1-64) | 32 (2-512) | |||||
a
Values are medians, with ranges given in parentheses. P was <0.001 for all differences between pre- and postvaccination sera. Postvaccination sera were obtained 6 weeks after the third dose.
b
A total of 24 and 26 individuals received MeNZB and MenBvac, respectively.
c
OMVs were the antigens in the ELISA, and live meningococci were the antigens in the remaining analyses.
d
P value for differences in responses to either vaccine strain between the two vaccine groups. NS, not significant.