Objective:This study aims to observe the protective effect of periodontitis gene vaccine pVAX1-HA2-FimA and pVAX1-HA2-FimA/IL-15 in SD rats with experimental periodontitis. Methods:Fifty-four male SD rats were randomly divided into 9 groups:Control group(normal saline group,group A),empty plasmid pVAX1 group(group B),periodontal disease group(group C),Experimental group[50 μg,100 μg,150 μg pVAX1-HA2-FimA group(D,E,F group)and 50 μg,100 μg,150 μg pVAX1-HA2-FimA/IL-15 group(G,H,I group)]. Experimental periodontitis model was established after nasal drip immunization of SD rats,and the relative expression levels of TNF- α and MMP-8 mRNA in gingiva were detected by RT-qPCR. The absorption of alveolar bone was observed and measured by stereomicroscopy. Results:①The TNF-α and MMP-8 mRNA in the gingival tissues of each experimental group were lower than that in the periodontal disease group,and the differences were statistically significant(P < 0.05). ②Compared with the pVAX1-HA2-FimA group,the amount of alveolar bone absorption in the pVAX1-HA2-FimA/IL-15 group with the same vaccine dose was lower,and the differences were statistically significant(P < 0.05). Conclusion:The periodontitis gene vaccines pVAX1-HA2-FimA/IL-15 and pVAX1-HA2-FimA have protective effects on SD rats with experimental periodontitis.