Table 1. Route of immunization against rectogenital infection in animal models.

Route	Advantages	Disadvantages	Feasibility
Oral	Easy to administer, convenient mode of remote immunization	No to low levels of rectogenital responses induced and risk of inducing oral tolerance	Practical for mass vaccination and preferred
Intranasal	Easy to administer, convenient mode of remote immunization	Inducing modest levels of cellular and humoral responses and weak protection, pre-existing immunity to some delivery vehicles, may exacerbate nasal or respiratory inflammation; risk of transport through olfactory nerve to brain.	Practical for mass vaccination
Intracolorectal	Local immunization inducing both cellular and humoral rectal and vaginal responses	Vaccination requiring facility and a trained professional, discomfort and accidental trauma may occur	Feasible for special treatment but impractical for mass vaccination
Intravaginal	Local immunization inducing humoral vaginal responses	Vaccination efficacy is influenced by the menstrual cycle and no responses induced in the large intestine	Feasible for special treatment but impractical for mass vaccination
Targeted oral	Easy to administer, passing through small intestine and selectively targeting large intestine to induce immune protective immunity comparable to intracolorectal immunization	Extra manufacturing procedures required but not significant	Practical for mass vaccination and preferred