Vaccines able to induce both secretory IgA for protection of mucosal surfac
es and systemic immunity to pathogens invading the host are of great intere
st in the war against infectious diseases. Mucosal vaccines trigger immune
cells in mucosal inductive sites and thus can induce immunity in both the m
ucosal and systemic compartments. This review presents a critical survey of
adjuvants and delivery systems currently being tested for mucosal immuniza
tion. A better understanding of cellular and molecular factors involved in
the regulation of mucosal immunity will help in the design of safer mucosal
vaccines to elicit the appropriate protective immune response to a given p
athogen.