Improved Production Process for Native Outer Membrane Vesicle Vaccine against Neisseria meningitidis

Abstract

An improved detergent-free process has been developed to produce vaccine based on native outer membrane vesicles (NOMV) against Neisseria meningitidis serogroup B. Performance was evaluated with the NonaMen vaccine concept, which provides broad coverage based on nine distinct PorA antigens. Scalable aseptic equipment was implemented, replacing undesirable steps like ultracentrifugation, inactivation with phenol, and the use of preservatives. The resulting process is more consistent and gives a higher yield than published reference processes, enabling NOMV production at commercial scale. Product quality met preliminary specifications for 9 consecutive batches, and an ongoing study confirmed real-time stability up to 12 months after production. As the NOMV had low endotoxic activity and induced high bactericidal titres in mice, they are expected to be safe and effective in humans. The production process is not limited to NonaMen and may be applicable for other N. meningitidis serogroups and other gram-negative pathogens. The current results therefore facilitate the late-stage development and clinical evaluation of NOMV vaccines.

Meningococcal Outer Membrane Vesicle Composition-Dependent Activation of the Innate Immune Response

“…This indicates that it is possible to have two different tactics for producing OMVs to induce similar immune responses. The lpxL1 nOMVs have the added benefit over wild-type dOMVs of being easier to produce and to better preserve potential antigens (11). The use of EDTA is known to stimulate OMV release but does not seem to influence the immune-stimulating properties, as in all the experiments where we used both types of OMVs, we did not observe any significant differences between lpxL1 sOMVs and nOMVs.…”

“…Although this method has been used successfully for OMV vaccines to control meningococcal outbreaks and is the basis for the fourth component of the recently approved Bexsero 4CMenB vaccine (28), it has the downside that DOC treatment complicates processing and removes potentially protective lipoproteins such as fHbp, an antigen of N. meningitidis known to induce serum bactericidal antibodies (9)(10)(11). To circumvent the need for DOC treatment, ge- netic modification of the LPS structure, such as by deletion of the lpxL1 gene, has been shown to result in a safe vaccine based on spontaneously released OMVs (29,30).…”

“…Therefore, if not removed or reduced by detergent treatment, the LPS present in isolated OMVs can cause serious adverse effects. The downside of detergent treatment is the removal of potential protective antigens from the outer membrane, such as the more loosely attached surface-exposed lipoprotein factor H binding protein (fHbp) (9,10), and a reduction of the long-term stability of the OMV vaccine (11).…”

A Meningococcal Outer Membrane Vesicle Vaccine Incorporating Genetically Attenuated Endotoxin Dissociates Inflammation from Immunogenicity

“…Wild-type OMVs were produced from N. meningitidis H44/76 (B:P1.7,16;F3-3), while nOMVs (Figure 1A), incorporating a genetically attenuated version of endotoxin, were produced from a H44/76 ΔRΔL mutant strain (16, 27). All OMVs were characterized by DLS for particle size (Figure 1B; Figure S1 in Supplementary Material), with all formulations falling within a range of 80–120 nm in diameter.…”

“…Briefly, OMVs were produced from N. meningitidis H44/76 (B:P1.7,16;F3-3) WT or derivatives. nOMVs were produced from a H44/76 ΔRΔL (15, 16, 27), resulting in a pentaacylated meningococcal LPS from the lpxL1 mutant N. meningitidis strain, lacking the secondary C12:0 acyl chain at the 2′-position of the lipid A. Detergent-extracted OMVs were produced from the WT strain or the ΔRΔL mutant (28). Adsorption to aluminum hydroxide (Sigma-Aldrich) was performed, as described elsewhere (29).…”