Session Title: VACCINE AND PREVENTION
BACTERICIDAL ACTIVITY AGAINST AN EXTENDED PANEL OF MENINGOCOCCAL STRAINS FOLLOWING IMMUNISATION WITH NOVEL SEROGROUP B MENINGOCOCAL VACCINES IN INFANCY
E.L. Su1, M.D. Snape1, T. Dawson1, A. Morant1, T. John1, B. Ohene-Kena1, R. Borrow2, J. Findlow2, P. Oster3, E. Miller4, A.J. Pollard1
1Oxford Vaccine Group, University of Oxford, Oxford, 2Vaccine Evaluation Unit, Health Protection Agency, Manchester, UK, 3Global Medical Affairs, Novartis Vaccines, Siena, Italy, 4Centre for Infections, Health Protection Agency, London, UK
Background: We previously reported that ≥93% of infants completing an early infant (2, 4, 6 and 12 month) or a late infant (6, 8 and 12 month) course of a serogroup B meningococcal (MenB) vaccine (rMenB+OMV) had human complement serum bactericidal antibody (hSBA) titres ≥1:4 against 3 meningococcal strains (44/76-SL, NZ98/254 and 5/99) expressing the vaccine antigens.
Methods: Sera obtained after completion of early or late infant courses of rMenB (containing factor H binding protein (fHBP) sub-variant 1.1, NadA and GNA2132) or rMenB+OMV (rMenB plus outer membrane vesicles from strain NZ98/254, expressing PorA P1.7-2,4) were tested for hSBA using 4 additional MenB strains: M00-242922 (ST:41, fHBP1.4, NadA-ve, PorA:P1.7-2,4); M01-240101 (ST:1049, fHBP1.11, NadA-ve, PorA:1.19-1,15-11); M01-240355 (ST:213, fHBP3.4, NadA low expression, PorA:P1.22,14) and M01-240364 (ST:11, fHBP 3.4, NadA+ve, PorA:P1.5,2).
Results: After an early infant course of rMenB+OMV, 80% of participants had hSBA titres ≥1:4 against M00-242922 (PorA homologous), 57% against M01-240101 (contains related fHBP), 11% against M01-240355 (fHBP, PorA and NadA heterologous) and 78% against M01-240364 (NadA homologous). After a late infant rMenB+OMV course, 100% of participants had hSBA titres ≥1:4 against M00-242922, 70% against M01-240101, 17% against M01-240355 and 90% against M01-240364.
For these four strains, rMenB alone was only immunogenic for M01-240364 (hSBA ≥1:4 in 70% (early infant) and 88 % (late infant) participants).
Conclusion: These data confirm that a course of rMenB+OMV in early or late infancy induces bactericidal antibody against strains expressing the vaccine antigens, further demonstrating the potential for improved vaccine prevention of MenB disease.