Journal of Vaccines & Vaccination

Outer membrane vesicles as an attractive candidate for pertussis vaccine

6^th Euro Global Summit and Expo on Vaccines & Vaccination

August 17-19, 2015 Birmingham, UK

Daniela F. Hozbor, Bottero D, Gaillard E, Rumbo M, Bartel E, Moreno G, Zurita E, Sabater D, Bravo S, Errea A, Flores D, Castuma C and Carriquiriborde F

Scientific Tracks Abstracts: J Vaccines Vaccin

Abstract:

Gram-negative bacteria naturally release lipid bilayer vesicles from the outer membrane. Outer membrane vesicles
(OMVs) range in size from approximately 20-200 nanometers in diameter and enclose many native bacterial antigens in
the spherical particles. The vesicles function in diverse roles including facilitation of the infection progression. Due to their
immunogenic properties, self-adjuvanticity and ability to be taken up by mammalian cells, OMVs are attractive candidates
as vaccine delivery platforms. We have developed a new vaccine against pertussis based on outer membrane vesicle (OMVs),
which have been shown to be safe and to induce protection in mice. Furthermore, it elicits a protective immune response
with a mixed Th1/Th2 profile and also induces a robust antibody response. We have characterized the composition of the
pertussis nanoparticles, finding >40 protein components, mostly membrane-bound proteins. The presence of a high number
of immunogens in the vaccine formulation is important since this may avoid the excessive selective pressure conferred by a
single or a few protective vaccine antigens. Our OMV-based vaccine exhibits adequate protection capacity against different
B. pertussis genetic background including those not expressing the virulence factor pertactin (PRN) that is also included in
commercial vaccines. Our formulation also is attractive economically, which is critical for its use in developing countries.
It is estimated that the final cost per dose is less than that of existing AP formulations based on several purified protein
immunogens, which impacts on the final cost of the vaccine. In our case a single process step is necessary for the production
of each B. pertussis and B. parapertussis nanoparticle.