Immunogenicity and Safety of a Combination of Two Serogroup B 1

1 MenBvac and MeNZB are safe and efficacious vaccines against serogroup B 2 meningococcal disease. MenBvac is prepared from a B:15:P1.7,16 meningococcal 3 strain (44/76) and MeNZB from a B:4:P1.7-2,4 strain (NZ98/254). 4 At 6-week intervals, healthy adults received three doses of MenBvac (25 μg), MeNZB 5 (25 μg) or MenBvac+MeNZB (12.5 + 12.5 μg dose) combined vaccine, followed by a 6 booster one year later. Two thirds of the subjects who received monovalent vaccine in 7 the primary schedule received the other monovalent vaccine as a booster dose. 8 The immune responses to the combined vaccine were of the same magnitude as the 9 homologous responses observed for each individual vaccine. At 6 weeks after the 10 third dose, 77% and 87% of the subjects in the combined group achieved SBA titers 11 ≥4 and 97% and 93% achieved ≥4-fold increase in opsonophagocytic activity against 12 strains 44/76 and NZ98/254, respectively. 13 For both strains, a trend of higher responses after the booster dose was observed in all 14 groups receiving at least one dose of the respective strain-specific vaccine. 15 Local and systemic reactions were common in all vaccine groups. Most reactions 16 were mild or moderate in intensity and there were no vaccine-related serious adverse 17 events. The safety profile of the combined vaccine was not different from those of the 18 separate monovalent vaccines. 19 In conclusion, use of either of the single vaccines or the combination of MenBvac and 20 MeNZB, may have considerable impact on the serogroup B meningococcal disease 21 situation in many countries. 22 AC CE PT ED Combined meningococcal group B vaccine Sandbu et al 3