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.