It is in the general knowledge of a person skilled in the art how to measure the cellular and/or antibody mediated immune response. In particular, it is clear to such person skilled in the art either to compare the cellular mediated immune response of the immunogenic composition of interest with cellular mediated immune response of the reference, or the antibody mediated immune response of the immunogenic composition of interest with that of the reference composition, but neither the cellular mediated immune response of a immunogenic composition of interest with the antibody mediated immune response of the reference or vice versa. Moreover, the cellular mediated immune response can be measured, for instance, by measuring the activation of cytotoxic T-cells by an immunogenic composition/antigen of interest. The antibody mediated immune response can be measured, for instance, by measuring the amount of antigen specific antibodies, generated in cause of the administration of the immunogenic composition comprising such antigen to an animal. The cellular and/or antibody mediated immune response can be measured, for instance, by using a mouse model, a cat model, a cattle model or a swine model. However, the assays as described in Example 4 and 5 shall be used as a reference assay for detecting the immunological response against M. hyorhinis and M. hyopneumoniae.
The term "same antigen" means, that nature of the antigens is identical. Thus, if the mycoplasma antigen of the immunogenic composition produced in a serum-reduced, eukaryotic cell system is whole inactivated bacterin of M. hyorhinis, than the same antigen means that the mycoplasma antigen of the cell-free system is also whole inactivated bacterin of M. hyorhinis. Furthermore, if the mycoplasma antigen of the immunogenic composition produced in a serum-reduced, eukaryotic cell system is prepared or purified according to a specific method, than the same antigen means that the mycoplasma antigen of the cell-free system is prepared or purified according to the same method.