Published online by Cambridge University Press: 31 July 2017
Chlamydia psittaci, depending on its serovar, can infect humans, birds, and other animals and livestock. Its economic impact on poultry production, especially on turkeys and chickens, and potential zoonotic risk have driven the search for an effective vaccination protocol to prevent and control the infection and shedding of the organism. Currently, no vaccine is approved for use against avian chlamydiosis despite efforts in the past decades. The present genomic era presents an opportunity to establish an effective vaccination scheme, taking advantage of the major outer membrane protein (MOMP) as the major protective antigen of C. psittaci. The plasmid DNA expressing MOMP can be coupled with optimisation of controllable factors during vaccination such as codon optimisation (through formation of polyplexes and lipoplexes), route of administration, vaccination schedule, addition of adjuvants/co-stimulatory factors such as cytokines and CpG motifs, and recombination with other poultry pathogens such as viruses. The development of an effective vaccine against C. psittaci will protect susceptible poultry from infection and production performance losses and reduce the zoonotic risk and minimise the emergence of antibiotic-resistant C. psittaci strains.