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 strainVaccinebIgG titer by ELISAc (kAU/ml)PdIgG titer by flow cytometryc (AU/ml)PdSBA assay resultc (titer)PdOPA assay resultc (titer)Pd
Prevaccination seraPostvaccination seraPrevaccination seraPostvaccination seraPrevaccination seraPostvaccination seraPrevaccination seraPostvaccination sera
NZ98/254 (vaccine strain for MeNZB)MeNZB20 (0-244)456 (164-660)<0.0013 (1-28)47 (8-895)NS1 (1-32)26 (1-416)0.0381 (1-32)48 (4-256)NS
MenBvac20 (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)MeNZB40 (0-264)268 (92-568)<0.0018 (1-147)41 (1-712)NS1 (1-28)6 (1-169)NS1 (1-32)16 (1-128)NS
MenBvac28 (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.