Secretory immunity following mutans streptococcal infection or immunization.

Salivary IgA antibody responses to mutans streptococci can be observed in early childhood, sometimes even before permanent colonization of the oral biofilm occurs. Many of these early immune responses are directed to components thought to be essential for establishment and emergence of mutans streptococci in the oral biofilm. Initial responses are likely to be modulated by antigen dose, by immunological maturity, and by previous encounters with similar antigenic epitopes in the pioneer commensal flora. Our understanding of these modulating factors is modest and is an opportunity for continued investigation. Under controlled conditions of infection, experimental vaccine approaches have repeatedly shown that infection and disease can be modified in the presence of elevated levels of antibody in the oral cavity. Protection can be observed regardless of antibody isotype or method used to actively or passively provide the immune reagent. Limited clinical trials have supported the utility of both of these approaches in humans. Refinements in antigen formulation, delivery vehicles, enhancing agents and routes of application, coupled with approaches that are timed to intercept most vulnerable periods of infection of primary and permanent dentition may well provide the healthcare practitioner with an additional tool to maintain oral health.