including
Salmonella strains, have been used as heterologous antigen carriers
for oral mucosal vaccines [35]; however, amajor concern is that the
attenuated pathogen is not suited for use in immunocompromised
or weak hosts, for whom it can potentially be pathogenic [19].
Therefore, the use of probiotic bacteria as an antigen delivery
vehicle has been considered as a key component of a novel oral
mucosal vaccine [14,16,19,36,37].