Method of obatining cochlear structures, vaccine compositions, adjuvants and interme- diates thereof

A method for obtaining cochlear structures from vesicles found in the outer membrane of live organisms, comprising the following steps:

• (a) preparing from outer membrane vesicles, of a solution with a total protein concentration between 3 and 6 mg/mL, and adding a non-ionic detergent is added at a concentration 10 times that of the proteins;
• (b) filtering through a membrane with a pore size of 0.2 μm, with the aim of sterilizing and eliminating vesicle aggregates;
• (c) executing a rotational dialysis or a tangential filtration against a solution containing concentrations of a multivalent ion, particularly Ca2+, Zn2+, or Mg2+, between 2.5 and 6.5 mM, at conditions buffered at pH 7.4±0.2;
• and
• (d) mechanically treating the resultant cochlear structures to homogenize the size of the particles.