Dental Caries Vaccine: Challenges for the 21st Century

The primary objective of this review is to highlight and update the progresses made so far in the battle front towards developing preventive and/or curative vaccines against dental caries for global consumption. Dental caries (tooth decay) is one of the most common diseases occurring in humans. A considerable research work has established that dental caries is an infectious disease and forms through a complex interaction among many environmental and host factors. Although various caries preventive strategies currently exist, development of an effective vaccine has been studied for more than three decades. Vaccines are immune-biological substances designed to produce specific protection against a given disease. They stimulate the production of a protective antibody and other immune mechanisms.

A variety of different categories of vaccines are developed such as whole cell vaccine, subunit vaccine, synthetic peptide vaccine, recombinant vaccine, DNA vaccine, conjugate vaccine, etc. The results of animal trials including active vaccination and passive immunization through different routes were encouraging relevant to protection against dental caries. Based on these results limited small scale human trials have been conducted with some experimental vaccines. Among them, Glucosyltransferase (GTF) from S. sobrinus combined with aluminum based adjuvant is prominent for protective immune responses. However, the phenomenon of human heart cross reactivity has to be overcome for further large scale human trials. Efforts are being made to modify various modalities of immunization to improve the duration and effectiveness of the immune responses. Two new fusion anti caries vaccines, pGJA-p/VAX and pGJG/GAC/VAX, encoding two important antigenic domains, PAc and GLU of S mutans as well as S sobrinus and successful in gnobiotic animals, seemed to be promising for future human trials.

The main obstacles of the twenty-first century, however, will be to remove rheumatic fever and human heart cross reactivity from an anti-caries vaccine and enhance its other human vaccination modalities. In actuality, the development of measles and polio vaccinations took close to 50 years. More difficult than landing a man on the moon is the search for an AIDS vaccine. Therefore, scientists are not disheartened by the numerous strange occurrences; rather, they are cautiously confident that a dental caries vaccine will become available sooner for use by people worldwide.