Formulation development of a plant-derived h1n1 influenza vaccine containing purified recombinant hemagglutinin antigen

Influenza is a prevalent, highly contagious and sometimes fatal respiratory disease. Vaccination provides an effective approach to control the disease, but because of frequent changes in the structure of the major surface proteins, there is great need for a technology that permits rapid preparation of new forms of the vaccine each year in sufficient quantities. Recently, using a safe, simple, time- and cost-effective plant viral vector-based transient expression system, the hemagglutinin antigen of H1N1 influenza A strain (HAC1), an H1N1 influenza vaccine candidate, has been produced in Nicotiana benthamiana plants. As a step toward the generation of a commercially viable subunit influenza vaccine, we developed HAC1 formulations in the presence and absence of an aluminum salt adjuvant (Alhydrogel®), analyzed their properties, and assessed immunogenicity in an animal model. Biophysical properties of HAC1 were evaluated using several spectroscopic and light scattering techniques as a function of pH and te...