“…Recent advancements have evolved to address the limitations that emerged with the evolution of novel therapeutic modalities from simple small molecules to more complex macromolecules, including nucleic acids, peptides, proteins, antibodies, and conjugates [ 1 ]. There’s immense interest in exploring the in vitro and in vivo behavior of drugs and vaccines to overcome biological barriers to reach target sites, and in expeditious translation from the lab to a manufacturing scale [ 2 ]. This Special Issue on “Emerging Trends and Translational Challenges in Drug and Vaccine Delivery” is the collection of those efforts by several researchers to address the unmet need of advanced drug and vaccine delivery systems.…”