Optimizing vaccine adjuvants to modulate immune responses: Perspectives and Challenges

Abstract

Introduction: Vaccination is one of the most effective interventions for the prevention of infectious diseases, being responsible for significantly reducing morbidity and mortality worldwide. Vaccine adjuvants act mainly through the activation of innate immunity, promoting the recruitment and activation of antigen-presenting cells, as well as the production of cytokines that guide the adaptive immune response. Thus, the search for more effective adjuvants capable of modulating different immunological profiles has driven the development of new strategies. Objective: The present study aims to analyze strategies for optimizing vaccine adjuvants, with an emphasis on innovative approaches, discussing their perspectives and challenges in modulating the immune response.
Materials and Methods: This is an integrative literature review with a qualitative and descriptive approach. After the screening stage and the application of inclusion and exclusion criteria, 21 articles were selected to compose this integrative review.
Results and Discussion: Vaccine adjuvants play a fundamental role in amplifying the immune response, especially in subunit vaccines, which alone present low immunogenicity. Among the different available platforms, emulsions, liposomes, saponin-based systems, and aluminum compounds stand out, each with specific characteristics that influence the magnitude and profile of the immune response. Toll-like receptor (TLR) agonists have emerged as important adjuvants in modulating the immune response.
Conclusion: The optimization of vaccine adjuvants, especially through approaches based on nanotechnology and immunomodulation, has demonstrated great potential for the development of more effective and safer vaccines capable of directing specific immune responses. As future perspectives, the use of more sophisticated nanostructured systems, personalized vaccines, and the integration of multiple adjuvants stand out to enhance and more precisely modulate the immune response.

Keywords: vaccine adjuvants, immune response modulation, nanotechnology.