Immune Response Following Oral Immunization with BCG Encapsulated in Alginate Microspheres

Background: Different methods have been used for BCG vaccination. Alginate microspheres are useful in delivery of vaccines to the gastrointestinal tract by oral route. Objective: To compare the immune response following oral microencapsulated and subcutaneous (SC) route administration of BCG vaccine in BALB/c mice. Methods: Alginate microspheres were produced by an internal emulsification method within olive oil. Four groups of mice were studied, including two groups receiving oral gavages of microencapsulated and free BCG, one receiving SC injection of BCG, and a control group. T cell proliferation, specific anti-BCG total IgG, and IgG subclasses (IgG1 and IgG2a) were compared between groups 5 and 12 weeks after vaccination. Results: The best result was achieved using oral microencapsulated form in comparison with oral BCG alone. Conclusion: Delivery of oral BCG with alginate microspheres is an effective way to induce immune response in BALB/c mice.