Can mRNA Vaccines Turn the Tables During the COVID-19 Pandemic? Current Status and Challenges

Abstract

The COVID-19 pandemic continues to affect millions of people across the world. The current global statistics for the disease are 111 million cases and 2.45 million deaths, with new cases emerging each day. Although several drugs including remdesivir have been approved for emergency use, they remain ineffective in bringing the infection under control. Therefore, there is a need for highly effective and safe vaccines against COVID-19. The recent advancements in mRNA vaccines have catapulted them to be forefront in the race to develop vaccines for COVID-19. Two mRNA vaccines, BNT162b2 and mRNA-1273, developed by Pfizer-BioNTech and Moderna Therapeutics, respectively, have been granted authorization for emergency use by the US Food and Drug Administration. Interim analysis of the clinical trials for BNT162b2 and mRNA-1273 vaccines reported an efficacy of 95% and 94.1%, respectively, after the second dose. The adverse events for both the vaccines have been found to be mild to moderate, with mostly injection-site reactions and fatigue. No serious adverse events have been reported. Moreover, Pfizer-BioNTech and Moderna Therapeutics have announced that their vaccines are effective even against the new strains (B.1.17 and B.1.351) of the virus. Both companies are now scaling up the production of the vaccines to meet the global demand. Although the long-term efficacy, safety, and immunogenicity of these vaccines is uncertain, there is hope that they can turn the tables against COVID-19 in this current pandemic situation.

Longevity of immunity following COVID-19 vaccination: a comprehensive review of the currently approved vaccines

“…Furthermore, It is a considerable challenge to assess the effective duration of vaccine-induced immunity. 11 , 12 More research is needed to investigate the long-term efficacy and safety of the vaccines and the impact of different factors on the longevity of the immune response. 10 This systematic review provided a summary of immune response profiles, type of antibody response, the onset of humoral immunity, and its duration following each currently approved COVID-19 vaccine.…”

COVID‑19 vaccination and IgG and IgA antibody dynamics in healthcare workers

“…Therefore, the first mRNA-based vaccine (Pfizer-BioNTech) was approved by the FDA and EMA (5,6). The approval of the Moderna vaccine on december 18, 2020 contributed to the list of approved vaccines for coVid-19 (7). Therefore, by February 18, 2021, almost a dozen vaccines were authorized worldwide and up to the date of the publication of the present study, even more may be approved and many more will be in the pipeline of development (8).…”

Nucleic Acid Vaccines for COVID-19: A Paradigm Shift in the Vaccine Development Arena

“…As such, DNA vaccines are associated with the risk of altering the genetic makeup of the host cell permanently (insertional mutagenesis). mRNA-based vaccines do not pose this risk as they do not enter the nucleus [123,124]. Naked DNA has low immunogenicity, and it is essential to include vectors, adjuvants and appropriate delivery methods to increase its immunogenicity.…”