MACACA-FASCICULARIS AS A MODEL IN WHICH TO ASSESS THE SAFETY AND EFFICACY OF A VACCINE FOR PERIODONTITIS

We have assessed Macaca fascicularis as a potential model in which to test the efficacy and safety of a vaccine for periodontitis. Twenty-ei ght animals were surveyed and 20 studied in more detail. Clinical peri odontal status was assessed, the subgingival microflora analyzed espec ially for the presence and proportions of Porphyromonas gingivalis and titers and avidities of serum antibodies reactive with P gingivalis m easured. Probing depths ranged from 0.90 mm to 3.80 mm, Gingival Index scores from 0.00 to 4.00 and Plaque Index scores from 0.00 to 3.00. A bout 40% of sites bled on probing. The animals manifested a subgingiva l flora characteristic of the anaerobic gram-negative bacteria found i n human periodontal pockets, including Actinobacillus actinomycetemcom itans, P gingivalis, Bacteroides forsythus, Campylobacter rectus, Prev otella intermedia and Fusobacterium nucleatum. P gingivalis was detect ed in 70 of 80 samples studied, ranging from 0.01% to 20% of the total flora. Serum antibody reactive with antigens of P gingivalis was obse rved in all animals, with titers ranging from 1.0 enzyme-linked immuno sorbent assay (ELISA) unit to 25 ELISA units and avidities from 0.10 M to 2.20 M. Antibody titer and maximum percentage of P gingivalis were inversely correlated, indicating that a humoral immune response may b e effective in reducing P gingivalis overgrowth. M. fascicularis appea rs to be an excellent model for use in vaccine development.