Aluminum hydroxide and calcium phosphate adjuvants in adsorbed tetanus and diphtheria vaccines: Immunologic vs histopathologic effects

Abstract

Abstract We aimed to study effects of aluminum hydroxide (AH) and calcium phosphate (CAP) adjuvants in potentiation of new tetanus and diphtheria vaccines that have been developed in our laboratory. AH gel or CAP nanoparticles were prepared in vaccine formulations in adsorbed tetanus or tetanus-diphtheria (Td) vaccines. Vaccine formulations were injected to 8-week old female Balb/c mice. Only phosphate buffered saline (PBS) was injected to control animals. Tissue samples, peripheral blood samples and spleen cells were collected from each mouse. Serum was separated by centrifugation of peripheral blood. Spleen cells were stained with anti-CD4-FITC, anti-CD8-PE, and anti-CD19-APC monoclonal antibodies. ELISA was performed to test presence of anti-tetanus or anti-diphtheria antibodies. We found that either a single dose or an additional booster doses did not change significantly the composition of lymphocyte distribution in AH and CAP adjuvant injected mice in comparison to the control animals. No significant difference was detected for CD4/CD8 ratio and for CD19-expressing cell number. However, presence of IgM and IgG antibodies that were specific for both tetanus and diphtheria toxins increased significantly following injection of vaccines. Granulomas and cyst formation after subcutaneous injections of CAP-containing vaccines at the site of injection were evaluated. Supported by Gazi University BAP, No: 64/2018-04.