The following is the summary of “Immunogenicity and safety of the meningococcal B recombinant (4CMenB) vaccine in allogeneic hematopoietic cell transplantation recipients” published in the December 2022 issue of Clinical microbiology and infections by Robin, et al.
While hematopoietic cell transplant recipients are at increased risk for invasive meningococcal (Men) illness, there is currently no published data on the efficacy of any MenB vaccination in this population (HCT). In this study, researchers analyzed the immunogenicity and safety of the 4CMenB recombinant vaccine (Bexsero) in adult HCT recipients. Patients could start receiving 2 doses of 4CMenB every 2 months after HCT. At baseline, one month after the second dosage, and again 12 months following enrollment, blood samples (sera) were taken. Serum bactericidal activity (SBA) against fHbp, NadA, PorAP1.4, and NHBA antigens was measured by using human complement (hSBA).
One criterion for one vaccination antigen was used to characterize the immunization response. If the patient’s hSBA titer was less than 4 before treatment began, a titer ≥4; (2) in patients with an hSBA titer ≥4 at baseline must be at least 4 times higher afterward. The median time since transplantation for the (40) individuals included in this analysis was 2.14 (0.57-13.03) years. Most patients had hSBA titers 4 for all vaccination antigens at baseline (32/40, 80%). Only 6 of 40 (15%) patients responded to the NHBA vaccination after 2 doses, whereas the proportion of patients with a titer a titer ≥4; (2) in patients with a hSBA titer ≥4 at baseline:4 was dramatically raised for fHbp (23/40, 57.5%), NadA (25/40, 62.5%), and PorA (31/40, 77.5%). 9 0%of patients (36/0) responded to ≥1 antigen.
After 9 months, however, only 23 of 37 (62.2%) patients were still protected by their antibodies. There was no serious adverse event recorded. Their safety data and a 90% response rate for a ≥1 vaccine antigen suggest that HCT patients can be safely vaccinated against 4CMenB beginning at 6 months post-transplant with a total of 2 doses.