As part of an ongoing series of updates in scientific areas of emphasis and opportunity, an expert panel was convened to discuss issues ranging from the feasibility and safety of developing and testing a vaccine against dental caries to marketplace realities. The panel heard latest findings from scientific experts in this area and then identified and deliberated on the issues. They concluded that NIDCR should continue to support basic research on mucosal immunology and suggested that priority be given to the passive immunization approach. The panel also raised several scientific, ethical and economic considerations related to the active immunization approach for the prevention of dental caries.
The panel pointed out the need for additional longitudinal data documenting the relationship among S. mutans levels, antibody levels and caries. One approach could involve studying all innate immune factors in children not colonized by S. mutans, despite having mothers with high caries levels. They questioned whether organisms other than S. mutans cause caries, since current vaccine strategies have targeted this organism. The possibility of other pathogenic organisms moving into the niche vacated by S. mutans was considered. Some concern was expressed about the safety of some of the antigens being proposed by the caries vaccine research groups. The panel raised the question of whether immunization of children, ages 1-2 years, whose immune systems are still developing, would present unique safety issues relative to older children or adults. They pressed for more precise identification of the target population for a caries vaccine and the rationale.
The panel noted public perception that vaccines (in general) alter normal development. This concern would have to be overcome for the public to accept a caries vaccine. Also explored was whether acceptance would be achieved if only “high-risk” populations were immunized.
The panel offered that a caries vaccine would have little chance of making it to marketplace. The biggest hurdle would be getting a CDC Advisory Committee on Immunization Practices (ACIP- http://www.cdc.gov/vaccines/recs/acip/default.htm) recommendation for routine use in all children. Without that, the panel said, industry will not make the vaccine. An ACIP recommendation is tied to economic-risk benefit, making it necessary to prove that a caries vaccine would be cost saving. More information about the burden of caries over time in terms of both economics and quality of life will be required.
In summary, the panel recommended that if NIDCR does pursue research supporting the development of a caries vaccine, we should re-frame our end goal to aim for proof of principle, stopping short of Phase 3 trials. Given the real-world barriers to a caries vaccine, the panel suggested that NIDCR consider using its resources to develop alternative means of solving the caries problem.