Immunogenicity and Protective Efficacy of Nucleic Acid-Based Vaccines Against COVID-19: A Systematic Review

To overcome the COVID-19 pandemic, the development of safe and effective vaccines is crucial. With the enormous information available on vaccine development for COVID-19, there are still grey areas to be considered when designing a potential vaccine. The rapid regulatory approval of nucleic acid-based vaccines was unique to the COVID-19; these vaccines were rapidly produced cost-effectively and with lesser risk of infectivity. Additionally, they demonstrated relative stability at room temperature (DNA). However, a comparative understanding of the immunogenic impact and efficacy of these vaccines is lacking. Immunogenicity is essential for developing and maintaining effective and long-lasting post-vaccination immunity to pathogenic microorganisms. This systematic review aims to assess and summarize the immunogenicity and protective efficacy of the nucleic acid-based vaccines against COVID-19. The Preferred Reporting Items for Systematic Reviews (PRISMA) recommendations were followed in this review. CASP tool was used for quality assessment of randomized controlled trials. All included studies employed a randomized control method, and the results demonstrated promising immune responses and effectiveness that provided high-level protection against COVID-19 infection. This study offers vital insights for advancing vaccine technology. Furthermore, it guides formulation, informs personalized vaccination strategies, and enhances global health preparedness, particularly in regions with limited vaccine access. Graphical Abstract