Ayushman Kumar Banerjee
With over 43 million COVID-19 cases having surfaced and more than 1.1 million deaths, researchers are relentlessly working round the clock to develop vaccines against the virus, SARS-CoV-2, which causes the COVID-19. This has led to a race for a vaccine against the novel coronavirus, and in this race, Moderna has devised a messenger RNA (mRNA-1273) based vaccine that encodes the spike proteins of the novel coronavirus. Moderna began its human trials as early as mid-March, eventually entering phase three in late July. Following the present trajectory and peer-reviewed articles suggesting its success, Moderna could also be on its way to licensing the primary mRNA vaccine for human use.
Certain fascinating characteristics of mRNA vaccines are the ability to mimic natural infections, stimulate a strong immune reaction, and therefore allowing the scope of combining several mRNAs to formulate cocktail solutions. As per Moderna’s patent application, WO2017070626, it reports that their vaccine consists of mRNAs encoding antigenic viral full-length S, S1, or S2 proteins from SARS-CoV and MERS-CoV virus, formulated in cationic lipid nanoparticles. Results published after their phase one trial showed 8 out of 45 candidates produced ‘neutralizing antibodies’ against the novel coronavirus.
The mRNA approach against COVID-19 may change how we look at immunization altogether.
Unlike traditional vaccine development methods, where inactivated or weakened virus or viral proteins are introduced within the body, mRNA vaccines circumvent the whole procedure of inactivating the virus or isolating coral proteins. This enables faster vaccine development. The schematic below shows how the mRNA vaccine would develop an immune response against the novel coronavirus.
One of the most challenging issues with mRNA vaccines is it’s weakened stability once inside the body as it breaks down faster compared to DNA, limiting the potency of mRNA vaccines. However, that has since been addressed after a 2005 study by the University of Pennsylvania which suggested chemical modifications making them more durable and stable.
Another novel approach that researchers have proposed explores the possibility of micro RNAs actings as potential therapeutic targets. MicroRNAs play a vital role in the regulation of gene expression and are also responsible for protecting the body from viruses. In the study published by Dr. Sadanand Fulzele and Dr. Carlos Isales, it was found that a key microRNA, which otherwise should attack COVID-19, diminishes due to chronic health conditions and as we age. This also explains why the elderly population with chronic diseases, like diabetes, cardiovascular conditions, are comparatively at more risk than the rest of the populace. The researchers suggest that a cocktail of multiple microRNAs if introduced through the nasal passage, might significantly improve the levels of these essential miRNAs to assist the older population in fighting the novel coronavirus.
In another study by Guterres et. al. they have identified 34 miRNAs for positive-sense viral RNA and 45 for negative-sense which can strongly bind to crucial SARS-CoV-2 genes. And after conducting a literature review for these miRNAs and their corresponding target they suggested that differentially expressed (DE) miRNAs hold the potential to help in screening COVID-19. Comparing DE miRNAs between early and late stages of infection could also assist in anticipating prognosis.
Also read: PHOSPHO1 AS A POTENTIAL TREATMENT FOR OBESITY AND DIABETES?
Reference
- Five things you need to know about: mRNA vaccines, Horizon: The EU Research & Innovation Magazine. (n.d.). https://horizon-magazine.eu/article/five-things-you-need-know-about-mrna-vaccines.html
- C. Liu, Q. Zhou, Y. Li, L.V. Garner, S.P. Watkins, L.J. Carter, J. Smoot, A.C. Gregg, A.D. Daniels, S. Jervey, D. Albaiu, Research and Development on Therapeutic Agents and Vaccines for COVID-19 and Related Human Coronavirus Diseases, ACS Cent Sci. 6 (2020) 315–331. https://doi.org/10.1021/acscentsci.0c00272.
- S. Price, Discover how a microRNA ‘nose cocktail’ could help fight COVID-19, Health Europa. (2020). https://www.healtheuropa.eu/discover-how-a-microrna-nose-cocktail-could-help-fight-covid-19/99962/
- A. Guterres, C.H. de Azeredo Lima, R.L. Miranda, M.R. Gadelha, What is the potential function of microRNAs as biomarkers and therapeutic targets in COVID-19?, Infection, Genetics and Evolution. 85 (2020) 104417. https://doi.org/10.1016/j.meegid.2020.104417
- Moderna’s mRNA vaccine reaches its final phase. Here’s how it works., Science. (2020). https://www.nationalgeographic.com/science/2020/05/moderna-coronavirus-vaccine-how-it-works-cvd/
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