Enhancement of the Immunity to Feline Triple Vaccines in Mice by Feline IL-15, IL-23 and Metabolic Regulatory Molecules

Feline calicivirus, herpesvirus, and panleukopenia virus are major infectious viruses to cause serious diseases in cats, yet their current trivalent vaccines have limitations in immune efficacy and duration of protection. This study assessed the immune-enhancing effects of novel adjuvants (feline IL-15, IL-23, and metabolic modulators) on vaccine responses. Forty mice were randomly assigned to four groups: Group A (composite adjuvants), Group B (metabolic regulatory molecules and Mn adjuvant), Group C1 (Mn adjuvant), and Group C2 (blank commercial vaccine). Results showed that Group A had significantly higher neutralizing antibody titers against calicivirus post-booster immunization, while both Group A and B exhibited enhanced antibody responses against herpesvirus and parvovirus. Notably, Group A displayed increased proportions of memory T cells, follicular B cells, and activated B cells. These findings suggest that the combination of feline IL-15, IL-23, and metabolic modulators are safe and effective immunoadjuvants for the trivalent feline vaccines to promote immune cell differentiation and antibody production, thus representing a promising strategy to optimize vaccine efficacy.