Protection of mice against gastric colonization of Helicobacter pylori by therapeutic immunization with systemic whole cell inactivated vaccines

- Evaluation of infectious dose using histopathologic scoring and Molecular techniques.
- Estimation of IgG immune response with respect to 2 vaccines though systemic route.
- Protection of therapeutic immunization against Helicobacter pylori infection in mice.
- Long term evaluation of infected and vaccinated animals.

The protective effect of therapeutic immunization with heat inactivated Helicobacter pylori cells administered with aluminum phosphate as an adjuvant was evaluated with “Swiss albino mice” infected with H. pylori Sydney strain 1 (SS1). The presence of bacteria in histological sections of the stomach was evaluated to confirm the colonization of H. pylori. The infection dose was determined to be 1 × 108 cells which resulted to be the optimal concentration to sustain infection for required time. Systemic immunization of H. pylori 26695 and SS1 Whole cell heat inactivated vaccine were induced on mice. The IgG titer levels of high dose adjuvant vaccine of both strains were proportionate on the 7th and 14th day. Subsequently on the 21st and 28th day SS1 high dose adjuvant revealed a higher titer value. The Probability values were <0.0001 which is statistically significant. Moreover, therapeutic immunization with SS1 (WC) vaccine confers efficacious protection against H. pylori infection in mice. These results represent strong evidence for feasibility of therapeutic use of whole cell based vaccine formulations against H. pylori infection in animal model.