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Review
. 2021 Oct 3;17(10):3288-3296.
doi: 10.1080/21645515.2021.1944742. Epub 2021 Jul 20.

Early approval of COVID-19 vaccines: Pros and cons

Md Arifur Rahman  1   2 , Md Sayeedul Islam  3
Affiliations
Review

Early approval of COVID-19 vaccines: Pros and cons

Md Arifur Rahman et al. Hum Vaccin Immunother. .

Abstract

The development of safe and effective vaccines has been an overriding priority for controlling the 2019-coronavirus disease (COVID-19) pandemic. From the onset, COVID-19 has caused high mortality and economic losses and yet has also offered an opportunity to advance novel therapeutics such as DNA and mRNA vaccines. Although it is hoped that the swift acceptance of such vaccines will prevent loss of life, rejuvenate economies and restore normal life, there could also be significant pitfalls. This perspective provides an overview of future directions and challenges in advancing promising vaccine platforms to widespread therapeutic use.

Keywords: COVID-19; DNA; SARS-CoV-2; Vaccine; mRNA.

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Figures

Figure 1.
Figure 1.
The mechanism of nucleic acid-mediated immune stimulation. The presence of naked mRNA/DNA from any source e.g. infectious organisms, diet or cellular DNA fragments, are sensed by a protein complex. Successive downstream signaling induces type-I interferon, which further stimulates the production of interferon stimulation genes (IGS). Abnormal expression of IGS might link to different immunological disorders (IDs). While second-generation mRNA vaccinations should be safer and may not strongly associated with this mechanism, long-term exposure to any nucleic acid in the form of vaccination may activate the nucleic acid-mediated immune sensing pathway, raising the risk of IDs
Figure 2.
Figure 2.
Schematic representation of antibody action and antibody dependent enhancement (ADE) to viral infection. (a) Antibodies generated after a few days of viral infection or successful vaccination, which in turn neutralize the viruses, enabling protection from further infection. (b) Secondary infection or infection after vaccination with a different viral strain causes failure of complete neutralization by the previously existing antibody. However, due to sharing some antigen similarities, partial neutralization may accelerate viral internalization by antibody-binding Fc receptors. Although nucleic-acid-based COVID-19 vaccines have been successfully approved and have shown no ADE complications in trials, including non-human primate animal studies, vaccinated individuals should be monitored across time
See this image and copyright information in PMC

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