“Recent Advances in the Development of a Streptococcus Mutans Vaccine”, 1988-12 ():
The effectiveness of anti-S. mutans SIgA, synthesized after oral immunization, in the protection of animals against dental caries provides encouraging evidence for the development of an effective and safe vaccine for human use.
However, certain points remain to be clarified:
the identification of the S. mutans antigens which are truly protective, common to the different S. mutans serotypes present in humans and devoid of any side effects in humans (cross-reactivity or adsorption to the tissues). Some of these problems may be resolved in the future by using monoclonal antibodies or gene cloning technology allowing the preparation of pure S. mutans protein antigens uncontaminated by other S. mutans proteins.
Certain differences exist between common human mucosal systems and those of the currently used rodent model: caries develop very quickly (2 months) in rats, and the salivary-induced SIgA response after oral immunization is sufficient to protect rats. However, in humans (or primates) caries develop over longer periods (1–2 years). Since antibody levels in the saliva decrease rapidly in absence of stimulation, a continuous sensitization of the local system is needed.
Therefore, a better understanding of the regulation of the human common mucosal system is very important. The use of either oral non-toxic adjuvant, or avirulent recombinant bacterial strains, able to recognize the GALT, could help considerably in inducing a durable salivary response and caries immunity.