Challenges in Live Whole Bacteria Vaccines Development and Manufacturing

Live attenuated bacteria can stimulate an excellent immune response that is nearly as good as that induced by an infection with the wild-type pathogen. Live microorganisms can provide continual antigenic stimulation giving sufficient time for memory cell production. However, since live bacteria vaccines contain living organisms, there is a degree of unpredictability raising some safety and stability concerns. To address safety concerns, appropriate mutations have to be introduced to provide adequate attenuation, while retaining the ability to induce immunogenic protection. Mutations introduced can present challenges in the manufacturing of the vaccine strain. Preservation of the vaccine strain, necessary for long term stability, provides additional challenges which need to be overcome.