mRNA Vaccines against SARS-CoV-2: Advantages and Caveats

Abstract

The application of BNT162b2 and mRNA-1273 vaccines against SARS-CoV-2 infection has constituted a determinant resource to control the COVID-19 pandemic. Since the beginning of 2021, millions of doses have been administered in several countries of North and South America and Europe. Many studies have confirmed the efficacy of these vaccines in a wide range of ages and in vulnerable groups of people against COVID-19. Nevertheless, the emergence and selection of new variants have led to a progressive decay in vaccine efficacy. Pfizer–BioNTech and Moderna developed updated bivalent vaccines—Comirnaty and Spikevax—to improve responses against the SARS-CoV-2 Omicron variants. Frequent booster doses with monovalent or bivalent mRNA vaccines, the emergence of some rare but serious adverse events and the activation of T-helper 17 responses suggest the need for improved mRNA vaccine formulations or the use of other types of vaccines. In this review, we discuss the advantages and limitations of mRNA vaccines targeting SARS-CoV-2 focusing on the most recent, related publications.

Time‐series transcriptome analysis of peripheral blood mononuclear cells obtained from individuals who received the SARS‐CoV‐2 mRNA vaccine

“…These results suggest that the booster BNT162b2 vaccination is insufficient to neutralize the Omicron variant. 26 Our results were similar to those of previous reports, not only in Japanese cases, but also in other countries. 27 Based on the transcriptome analysis results of the time-series comparison (between T1 and T4), specific characteristics were observed at each time point.…”

“…Notably, the neutralizing activity against the Omicron variant was low on Day 180, and increased with high variability on Day 360. These results suggest that the booster BNT162b2 vaccination is insufficient to neutralize the Omicron variant 26 . Our results were similar to those of previous reports, not only in Japanese cases, but also in other countries 27 …”

New Vaccine Platforms—Novel Dimensions of Economic and Societal Value and Their Measurement

“…In fact, several combination vaccine candidates against seasonal respiratory diseases utilizing next-generation vaccine platforms (e.g., Flu-COVID, Flu-RSV, and Flu-COVID-RSV) are currently being tested in Phase 2/3 clinical programs and vaccines with multiple strains of the same virus are already available to the public (e.g., FluMist Quadrivalent) [ 60 , 63 ]. mRNA-based vaccine development has even opened the doors to targeting diseases caused by latent viruses (e.g., cytomegalovirus [CMV] and human immunodeficiency virus [HIV]), enteric viruses (e.g., noroviruses), and bacteria (e.g., Lyme disease) [ 64 , 65 , 66 , 67 , 68 , 69 ].…”

COVID-19 Vaccines: Where Did We Stand at the End of 2023?

“…The most innovative approach to COVID-19 vaccines comprises mRNA-based approaches, where the synthetic mRNA introduced into the cytoplasm of host cells produces large quantities of antigen [ 158 ]. However, the single-stranded structure of mRNA makes it sensitive to degradation by cellular RNases, which has been addressed by the introduction of chemical modifications and anti-reverse cap analogs (ARCAs) [ 158 ]. The efficacy of mRNA delivery and protection against degradation have also been addressed by various nanoparticle (NP) formulations.…”