Novel adjuvants and innovative combinations of adjuvants (Adjuvant Systems) have facilitated the development of enhanced and new vaccines against re-emerging and challenging pathogenic microorganisms. Nonetheless, the efficacy of adjuvants is influenced by various factors, and the same adjuvant may generate entirely different immune responses when paired with different antigens. Herein, we combined the MPXV-B6R antigen with BC02, a novel adjuvant with proprietary technology, to assess its capability to induce both cellular and humoral immunity in mouse models. Mice received two intramuscular injections of B6R-BC02, which resulted in the production of MPXV-specific IgG, IgG1, and IgG2a antibodies. Additionally, it elicited strong MPXV-specific Th1-oriented cellular immunity and persistent effector memory B-cell responses. The advantages of BC02 were further validated, including rapid initiation of the immune response, robust recall memory, and sustained immune response induction. Although the potential of immunized mice to produce serum-neutralizing antibodies against the vaccinia virus requires further improvement, the exceptional performance of BC02 as an adjuvant for the MPXV-B6R antigen has been consistently demonstrated.

Tuberculosis (TB) remains one of the most significant challenges to global public health. Vaccine development is a critical strategy for the prevention and control of TB. However, evaluating the protective efficacy of TB vaccines faces numerous challenges, particularly in the selection of animal models and bacterial strains. Variations in animal models, challenge strains, challenge routes, and doses can significantly impact the outcomes of preclinical evaluations. This article highlights the importance of standardizing preclinical evaluation models, summarizes the animal models and challenge strains used in novel TB vaccine candidates, efficacy studies, and discusses the advantages and limitations of commonly used animal models in TB vaccine research. It also points out the differential performance of various animal models in simulating protection and pathology. Given the current limitations of using a narrow range of challenge strains and the lack of standardized infection routes and doses, this article calls for the establishment of more standardized challenge strains and the development of standardized evaluation models to improve the reliability and generalizability of new TB vaccine efficacy assessments.