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Immunogenicity studies with a genetically engineered hexavalent PorA and a wild-type meningococcal group B outer
E Rouppe van der Voort1, M Schuller, J Holst
1Laboratory for Vaccine Research, National Institute of Public Health and the Environment, Antonie van Leeuwenhoeklaan 9, Bilthoven, Netherlands.
Abstract:
The immunogenicity of two meningococcal outer membrane vesicle (OMV) vaccines, namely the Norwegian wild-type OMV vaccine and the Dutch hexavalent PorA OMV vaccine, were examined in infant cynomolgus monkeys. For the first time, a wild-type- and a recombinant OMV vaccine were compared. Furthermore, the induction of memory and the persistence of circulating antibodies were measured. The Norwegian vaccine contained all four classes of major outer membrane proteins (OMP) and wild-type L3/L8 lipopolysaccharide (LPS). The Dutch vaccine consisted for 90% of class 1 OMPs, had low expression of class 4 and 5 OMP, and GalE LPS. Three infant monkeys were immunised with a human dose at the age of 1.5, 2.5 and 4.5 months. Two monkeys of each group received a fourth dose at the age of 11 months. In ELISA, both OMV vaccines were immunogenic and induced booster responses, particularly after the fourth immunisation. The Norwegian vaccine mostly induced sero-subtype P1.7,16 specific serum bactericidal antibodies (SBA), although some other SBA were induced as well. The antibody responses against P1.7,16, induced by the Norwegian vaccine, were generally higher than for the Dutch vaccine. However, the Dutch vaccine induced PorA specific SBA against all six sero-subtypes included in the vaccine showing differences in the magnitude of SBA responses to the various PorAs.
Insights
Two meningococcal outer membrane vesicle (OMV) vaccines were compared in infant monkeys. Both vaccines were immunogenic, but the Dutch vaccine induced broader antibody responses across more PorA subtypes.
Area of Science:
- * Immunology
- * Vaccinology
- * Microbiology
Background:
- * Meningococcal outer membrane vesicle (OMV) vaccines are crucial for preventing bacterial meningitis.
- * Comparing wild-type and recombinant OMV vaccines provides insight into vaccine immunogenicity.
- * Infant cynomolgus monkeys serve as a relevant model for studying vaccine responses.
Purpose of the Study:
- * To compare the immunogenicity of a wild-type OMV vaccine and a hexavalent PorA OMV vaccine in infant monkeys.
- * To assess the induction of memory and persistence of circulating antibodies following vaccination.
- * To evaluate the breadth and magnitude of serum bactericidal antibody (SBA) responses.
Main Methods:
- * Infant cynomolgus monkeys were immunized with two different OMV vaccines at multiple time points.
- * Serum bactericidal antibody (SBA) assays were used to measure vaccine-induced antibody responses.
- * Enzyme-linked immunosorbent assays (ELISA) were employed to assess immunogenicity.
Main Results:
- * Both OMV vaccines demonstrated immunogenicity and induced booster responses, especially after a fourth dose.
- * The Norwegian wild-type OMV vaccine primarily induced antibodies against sero-subtype P1.7,16.
- * The Dutch hexavalent PorA OMV vaccine elicited broader SBA responses against all six vaccine-included PorA sero-subtypes.
Conclusions:
- * Both OMV vaccines are immunogenic in infant monkeys.
- * The Dutch hexavalent vaccine offers broader protection by inducing antibodies against multiple PorA subtypes.
- * Further research can optimize OMV vaccine formulations for comprehensive meningococcal disease prevention.