Ali et al. (2026). International Journal of Infectious Diseases. doi: 10.1016/j.ijid.2026.108752
…growth CHBA plate after a 4-h incubation. A volume of 10 µL of the bacterial suspension was added to each well of the microtiter plate. A volume of 10 µL of “active” antibody depleted human complement (Pel-Freeze, Inc., Brown Deer, WI) was added to all wells except the sample control wells for viable cfu and sample non-complement mediated lysis control, to which heat-inactivated antibody depleted human complement…
Pel-Freez products cited: Human Complement, Pooled, IgG/IgM Depleted (34010)
Abstract
<h4>Objectives</h4>Bexsero (4CMenB) and Trumenba (MenB-fHbp) were designed and licensed to protect against meningococcal serogroup B disease; however, the antigens in these vaccines are shared among other meningococcal serogroups. This study assessed the immunogenicity of the two licensed serogroup B vaccines against a hyperinvasive serogroup X strain.<h4>Methods</h4>Sera from adults immunized with either 4CMenB (before and after one, two, or three doses of vaccine) or MenB-fHbp (before and after two doses) were assayed in the serum bactericidal antibody (SBA) assay against serogroup X strain BF 2/97.<h4>Results</h4>A four-fold increase in SBA titers was observed in 70.0% (95% confidence interval: 45.7-88.1) and 51.5% (95% confidence interval: 41.3-61.6) of subjects after 2 doses of 4CMenB and MenB-fHbp, respectively. A significant increase in SBA geometric mean titers and percentage of subjects with SBA titers greater than or equal to four from baseline to after two doses of both serogroup group B vaccines was observed.<h4>Conclusion</h4>These data provide evidence that the licensed serogroup B vaccines can induce bactericidal antibodies against serogroup X, but it is noted the optimal control for serogroup X would be use of a conjugate vaccine that reduces acquisition of carriage and gives direct protection.