The vaccines presently used by injection are called subunit or split vaccines. This means that two specific proteins attached to the surface of the virus have been purified and subsequently used in the vaccine.

These proteins are called hemeagglutinin (H) and neuroamidase (N). Different strains of the virus have different variants/combinations of these proteins. Today there are more than 10 different variants known of both the hemeagglutinin and the neuroamidase. Furthermore, there are a number of sub-variants within each group. For example, one of the most common influenza viruses is called H3N2, another is called H5N1, which have been named “bird flu”.

Eurocine is developing a nasal vaccine that contains killed whole virus particles. Using whole virus give rise to a stronger immune response and stronger cross protection. To further enhance the immunological response and cross protection, the Eurocine’s adjuvant is added.

Adding the Eurocine adjuvant also results in a possibility to reduce the dose of the killed virus particles. If a pandemic will happen, this fact may be of utmost importance since we in such a situation may encounter a shortage of influenza vaccine.

Another important issue related to the use of whole virus is that the production of virus is simplified.