Crucell N.V. presents data demonstrating that their new system for vaccination, called AdVacTM, stimulates a stronger immune response, with improved safety. The data will be presented at the 4th annual meeting of the American Society for Gene Therapy (ASGT) in Seattle, Washington.
As part of its vaccine development program, Crucell has developed a new gene delivery system for vaccination purposes that better stimulates an immune response.
Current gene delivery systems (vectors) are derived from human adenovirus serotype 5, a common human common cold virus. These vectors need to be administered in high doses, because they poorly transduce the key target cells that elicit immune responses. Moreover, most people have been exposed to this type of adenovirus. As a result, current adeno-vaccines are very rapidly inactivated by the anti-adenovirus antibodies present in these individuals.
Crucell's new delivery system, AdVacTM, is based on another type of adenovirus (serotype 35). The data presented today by Crucell show that the new AdVacTM vector in fact efficiently binds to and transduces cells that elicit a strong immune response. Furthermore, in contrast to the currently used vectors, the AdVacTM vector is not inactivated by the anti-adenovirus antibodies that are present in the majority of individuals. Finally, the vector does not infect liver cells, which is an unwanted side effect of currently used vectors.
As a consequence, Crucell expects that AdVacTM-based vaccines will result in strong immune responses, while using a 100-fold lower dose compared to current adeno-vaccines, improving overall safety and efficacy of the vaccines.
AdVacTM forms a further improvement of Crucell's PER.C6TM technology for vaccines. Crucell applies its PER.C6TM cell line for the development of its influenza vaccine. Furthermore, PER.C6TM is currently used in clinical development by a number of pharmaceutical and biotech companies, including Merck & Co., Inc. who are using the PER.C6TM technology in their HIV-1 vaccines research program.