Fig. 3

NPs are based on lipids and the structure of messenger RNA. An mRNA molecule has the following components: a 5′ cap, 3′ UTR, open reading frame, poly (A) tail, and 5′ and 3′ untranslated regions (UTRs). The majority of mRNA vaccines are delivered via lipid nanoparticles (LNPs). LNPs often include lipid components such as cholesterol, phospholipids, ionizable lipids, and PEG-conjugated lipids. LNPs carrying antigen mRNA are employed to create Mpox mRNA vaccines, and the production and localization of these antigens in transfected cells are shown in Figure C. DCs and other APCs take up mRNA-LNPs or locally generated antigens. To stimulate CD4 and CD8 T cells, these APCs must first go to the lymph nodes. CD8 T cell priming leads to the production of cytotoxic T lymphocytes, which may eliminate pathogens by destroying them from the inside. T follicular helper (Tfh) cells and Th1 cells are two possible outcomes of antigen priming of CD4 T cells. Activation of a germinal center (GC) response is aided by Tfh cells. Vaccination causes GC reactions, which lead to the development of AB-secreting LLPCs and affinity-matured memory B cells (MBCs). Class flipping of antibodies (ABs) generated by LLPCs to either Th1- or Th2-associated Abs is influenced by the Tfh cell skew toward the Th1 or Th2 phenotype [116]