Adjuvanted pandemic influenza vaccine: variation of emulsion components affects stability, antigen structure, and vaccine efficacy

Abstract

Please cite this paper as: Fox et al. (2012) Adjuvanted pandemic influenza vaccine: variation of emulsion components affects stability, antigen structure, and vaccine efficacy. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12031. Abstract Background Adjuvant formulations are critical components of modern vaccines based on recombinant proteins, which are often poorly immunogenic without additional immune stimulants. Oil‐in‐water emulsions comprise an advanced class of vaccine adjuvants that are components of approved seasonal and pandemic influenza vaccines. However, few reports have been published that systematically evaluate the in vitro stability and in vivo adjuvant effects of different emulsion components. Objectives To evaluate distinct classes of surfactants, oils, and excipients, for their effects on emulsion particle size stability, antigen structural interactions, and in vivo activity when formulated with a recombinant H5N1 antigen. Methods Emulsions were manufactured by high pressure homogenization and characterized alone or in the presence of vaccine antigen by dynamic light scattering, zeta potential, viscosity, pH, hemolytic activity, electron microscopy, fluorescence spectroscopy, and SDS‐PAGE. In vivo vaccine activity in the murine model was characterized by measuring antibody titers, antibody‐secreting plasma cells, hemagglutination inhibition titers, and cytokine production. Results We demonstrate that surfactant class and presence of additional excipients are not critical for biological activity, whereas oil structure is crucial. Moreover, we report that simplified two‐component emulsions appear more stable by particle size than more complex formulations.Finally, differences in antigen structural interactions with the various emulsions do not appear to correlate with in vivo activity. Conclusions Oil‐in‐water emulsions can significantly enhance antibody and cellular immune responses to a pandemic influenza antigen. The dramatic differences in adjuvant activity between squalene‐based emulsion and medium chain triglyceride‐based emulsion are due principally to the biological activity of the oil composition rather than physical interactions of the antigen with the emulsion.

Adjuvant formulation structure and composition are critical for the development of an effective vaccine against tuberculosis

“…For example many TLR4 agonists are insoluble and prone to aggregation without proper formulation. Besides squalene-based nanoemulsion formulations of GLA, we have previously reported on the development of triglyceride-based nanoemulsions [19-22], aqueous nanosuspensions [19,23], liposomal formulations [24], and an alum-adsorbed microparticulate formulation of GLA [25]. Each of these formulations includes lipid-based excipients but differs significantly in particle morphology, surface characteristics, and size.…”

Adjuvant-induced Human Monocyte Secretome Profiles Reveal Adjuvant- and Age-specific Protein Signatures

“…Most current adjuvanted vaccines have been developed empirically, formulating antigen with adjuvants, such as aluminum salts or oil-in water emulsions, whose mode of action, especially in different age groups, is incompletely elucidated (3, 4). One approach to increase vaccine immunogenicity in these vulnerable populations is to use and develop adjuvants that are particularly effective in overcoming age-specific limitations in immune system function (5–7). Characterization of adjuvant action in different age groups may inform more rational adjuvant design.…”

Technology transfer of oil-in-water emulsion adjuvant manufacturing for pandemic influenza vaccine production in Romania: Preclinical evaluation of split virion inactivated H5N1 vaccine with adjuvant

“…5 EM022 contains 2.5% v/v squalene emulsified by non-ionic surfactants whereas SE contains 2% v/v squalene emulsified by phospholipid and block copolymer. 2,6 In this third mouse experiment, the mouse strain and immunization regimen remained identical to the previous 2 mouse experiments described above, although group size was reduced to 10 animals. Immunogenicity analyses were focused only on HI titers against homologous and heterologous strains (Fig.…”

“…2 EM022 is a squalene emulsion with polysorbate 80 (NOF Corp.) and sorbitan trioleate (Sigma-Aldrich) emulsifiers in a 10 mM citrate buffer (J. T. Baker) manufactured by high pressure homogenization as described earlier. 6 Antigen Split virion inactivated influenza H5N1 antigen was produced by Sanofi Pasteur (designated SP hereafter) obtained from the National Pre-Pandemic Influenza Vaccine Stockpile (NPIVS) through HHS or by CI. For antigen produced by CI, the manufacturing process and quality control tests followed the same process described in detail previously (2) or with modification as described below and illustrated schematically in Figure 1.…”