From genetic code to global health: the impact of nucleic acid vaccines on disease prevention and treatment

Abstract

Vaccinology has revolutionized modern medicine, delivering groundbreaking solutions to prevent and control infectious diseases while pioneering innovative strategies to tackle non-infectious challenges, including cancer. Traditional vaccines faced inherent limitations, driving the evolution of next-generation vaccines such as subunit vaccines, peptide-based vaccines, and nucleic acid-based platforms. Among these, nucleic acid-based vaccines, including DNA and mRNA technologies, represent a major innovation. Pioneering studies in the 1990s demonstrated their ability to elicit immune responses by encoding specific antigens. Recent advancements in delivery systems and molecular engineering have overcome initial challenges, enabling their rapid development and clinical success. This review explores nucleic acid-based vaccines, including chemically modified variants, by examining their mechanisms, structural features, and therapeutic potential, while underscoring their pivotal role in modern immunization strategies and expanding applications across contemporary medicine.

Fig. 1. Representation of key milestones in the advancement of DNA-based therapeutics, emphasizing the technological progression of DNA methodologies and their integration into biomedical and scientific frameworks.

Fig. 2. Timeline of milestones in RNA-based vaccine development. This illustration presents key milestones in the development of mRNA therapeutics, emphasizing the broader advancement of mRNA technology and its evolution as a platform for vaccine development.

Fig. 3. DNA vaccination induces both humoral and cellular immune responses. DNA is introduced into antigen-presenting cells (APCs; e.g., dendritic cells) or into keratinocytes/myocytes. In keratinocytes/myocytes: expressed antigens are released and captured by dendritic cells, processed, and presented via MHC-II to CD4⁺ T cells. In APCs: intracellular expression of antigens enables presentation via MHC-I and MHC-II, activating CD8⁺ and CD4⁺ T cells. B cell receptors recognize antigens from keratinocytes/myocytes; with CD4⁺ T cell help, B cells produce antigen-specific antibodies.

Fig. 4. Toll-like receptors (TLRs) in APC activation and immune modulation. Surface (TLR1/2/4/5/6/10) and endosomal (TLR3/7/8/9) TLRs recognize pathogen-associated molecular patterns (PAMPs), including licensed and experimental adjuvants (e.g., MPL, CpG, GLA-SE, BCG). TLR signaling in APCs enhances antigen presentation and co-stimulatory signaling (CD80/CD86), promoting T cell activation. T cell-intrinsic TLR activity (bottom right) supports Th1 polarization, regulatory T cell induction, and effector T cell activation—underlining the therapeutic value of TLR agonists in vaccine adjuvant design.

Fig. 5. Cytosolic RNA sensors RIG-I, MDA5, and LGP2 detect viral RNA to trigger antiviral signaling. RIG-I recognizes 5′-triphosphate RNA, while MDA5 senses long dsRNA, including poly I:C.

Fig. 6. Composition of DNA vaccine plasmids. The upper section shows the eukaryotic expression cassette, enabling high-level antigen expression in host cells. It includes a promoter, Kozak sequence, gene of interest, stop codon, and polyadenylation signal (poly A). The lower section represents the prokaryotic backbone, required for plasmid replication and maintenance in bacteria, containing a prokaryotic origin of replication and a selectable marker.

Fig. 7. Optimization strategies in next-generation vaccine design, focusing on four components: promoter (e.g., hybrid promoters with APC-specific activity), antigen (e.g., codon optimization, invariant chain fusion, MHCI/II combinations), adjuvant (e.g., signaling molecules or cytokines expressed in cis), and backbone (e.g., immunostimulatory sequences, minicircle vectors).

Fig. 8. mRNA structure: 5′-Cap, 5′-untranslated region (UTR), coding sequence ending with a stop signal, 3′-UTR, poly (A) tail located at the 3′-end.

Fig. 9. 5′-cap modifications.

Fig. 10. DNA vaccine carriers: liposomes, polymers, virosomes, CPPs, live bacteria.

Fig. 11. Chemical structures of DOTAP, DOTMA, DOPE and ALC-0315 and SM-102 LNPs.

Fig. 12. Properties, origin and structure of the cell penetrating peptides.

Fig. 13. Structure of cationic nucleopeptide-based carrier.

Fig. 14. Structure of the most commonly employed synthetic cationic polymers.

Fig. 15. DNA-based vaccine platforms designed to address the antigenic diversity characteristic of the influenza virus.

Fig. 16. Development of DNA vaccines and clinical trials for HIV through a disease-specific targeting approach.

Fig. 17. Development of DNA vaccines and clinical trials for HBV through a disease-specific targeting approach.

Fig. 18. Development of DNA vaccines and clinical trials for SARS-CoV-2 through a disease-specific targeting approach.

Fig. 19. Development of DNA vaccines and clinical trials for prostate and breast cancer using disease-specific targeting approaches.

Fig. 20. RNA-based vaccines and clinical trials targeting influenza through disease-specific strategies.

Fig. 21. RNA-based vaccines and clinical trials targeting SARS-CoV-2 through disease-specific strategies.

Fig. 22. RNA-based vaccines and clinical trials targeting cancer through disease-specific strategies.

Alessandra Del Bene

Antonia D'Aniello

Salvatore Mottola

Vincenzo Mazzarella

Roberto Cutolo

Erica Campagna

Prof. Rosaria Benedetti

Prof. Lucia Altucci

Prof. Sandro Cosconati

Prof. Salvatore Di Maro

Prof. Anna Messere