Zhang, Y., et al. CD25+ cell depletion enhances protective immunity of PR8 inactivated influenza vaccine in aged mice. Virology, 2026 Aug, 621:110938. PMID: 42107283

This paper highlights the synergistic potential of combining saponin-based ISCOM adjuvants with immune regulatory modulation, specifically transient depletion of CD25+ regulatory T cells, to enhance influenza vaccine responses in aged mice. 

The study demonstrates that while ISCOMs alone significantly boost antibody titers and protection, their effectiveness is further amplified when paired with targeted CD25+ cell depletion, resulting in more balanced IgG subclass responses, lowered lung viral loads, and complete protection against lethal influenza challenge. 

This research is particularly interesting and unique because it emphasizes the dual role of saponin adjuvants not only as potent immunostimulants that activate humoral and cellular immunity but also as part of a novel immunomodulatory approach that leverages their compatibility with immune regulatory pathway manipulation. The findings underscore the importance of optimizing saponin-based adjuvants in vulnerable populations, like the elderly, by combining them with strategies that transiently modify immune regulation to overcome immunosenescence and maximize vaccine efficacy.

Click here to access the full scientific paper.