Animal vaccine revolution: Nanoparticle adjuvants open the future of vaccinology.

In recent years, the rapid development of nanoparticle adjuvants has greatly facilitated the treatment and prevention of infectious diseases in humans and animals. The remarkable success of mRNA nanovaccines against SARS-CoV-2 has accelerated the advancement of nanoparticle adjuvant technologies in the era of precision medicine. Significant progress has been made in researching nanovaccines for major animal infectious diseases, such as porcine epidemic diarrhea, avian influenza, porcine reproductive and respiratory syndrome, bovine viral diarrhea, foot-and-mouth disease, African swine fever, and Newcastle disease. This article reviews the nanoparticle adjuvants under investigation for animal use, emphasizing their diverse mechanisms of action and immunological properties, and analyzes the physicochemical factors influencing their immune-enhancing effects. On this basis, we discuss future prospects and key challenges that need to be addressed, aiming to provide valuable references for the development of novel animal vaccine adjuvants.