Dear all, I am currently working to a develop novel subunit vaccine for a poultry disease. The initial approach is first discover a potential immunogen, clone and express the immunogen, perform a vaccination using the recombinant protein as a vaccine, and then challenge the vaccinated animals with the infectious agent. We don't plan to produce the vaccine using the recombinant DNA technology (due to the cost consideration), but rather find the time when the immunogen is optimally expressed in the agent so we can harvest them. To do so, we need to develop ELISA and mAb against the immunogen. I would like to know, what approach is usually done to develop novel mAbs as in this case? Assuming the mAbs is not available in the market yet. Any examples from different diseases are welcome too. Thank you in advance for your time and help.