Immunological memory to vaccines.

The extraordinary success of vaccines saving lives and improving human health is predicated on immune memory. Within the armamentarium of adaptive immunity, a holistic view of the different components contributing to immune protection is important for understanding the myriad benefits of vaccines. This review presents the current understanding of vaccine-generated memory, integrating layers of immunity including B cells, CD8+ T cells, CD4+ T cells, and antibody responses, with emphasis on human vaccine data. Functions and durability of distinct memory types are considered, including those of tissue-resident and circulating cells as well as hybrid immunity, and within this context, common misconceptions and important next questions are discussed. Understanding the multifaceted layers that underlie protective immunity can guide future vaccines and broader immune-focused interventions. A video lecture accompanies this review (https://youtu.be/8DeZJ6V7nuI). VIDEO ABSTRACT.