Short description of the Project: Development of viral vector vaccines/marker vaccines against avian influenza
For the control of avian influenza, mainly classic inactivated viruses have been used so far. Their main disadvantage for practical application however is that they must be administered individually by injection. Furthermore, vaccination interferes with the differentiation of immunized and field virus-infected animals. We have recently been able to insert the haemagglutinin genes of highly pathogenic avian influenza viruses (HPAIV) of former outbreaks into the genomes of attenuated viruses and to protect chickens effectively against challenge infections with the respective HPAIV strains using these recombinants (Veits et al., 2003; Veits et al., 2006). These recombinant live vaccines are not only easy to apply by spray or drinking water, they also enable the differentiation of vaccinated and virus-infected animals by means of simple serological tests. Best protective efficacy was given with close homology of the antigenic component between vaccine and challenge virus (Römer-Oberdörfer et al., 2008). Therefore, the primary aim of the project is the development of vaccines against recent H5N1 HPAIV, but also against other subtypes of avian influenza viruses. The vector viruses will be modified to enable a quick response to changes of field viruses and for improvement of efficacy, further AIV antigens are to be identified and expressed in different combinations. In the frame of this project, there are also collaborations with other scientific institutions (e.g. PEI) working on the development of marker vaccines against HPAIV.