Messenger RNA (mRNA) vaccines teach our cells how to make a protein that will trigger an immune response inside our bodies. mRNA vaccines contain messenger RNA (mRNA), a single-stranded RNA molecule that complements DNA.
It is created in the nucleus, when DNA is transcribed by RNA polymerase to create pre-mRNA. Pre-mRNA is then spliced into mRNA, which is exported from the nucleus to the cytoplasm and “read” by ribosomes (the translation machinery of cells). Ribosomes then make proteins. mRNA vaccines use lab-created mRNA encapsulated within nanoparticles.
Translation of the mRNA results in the development of a protein antigen that triggers an immune response. mRNA vaccines are required to be kept at sub-zero temperatures. mRNA vaccines combine desirable immunological properties with an outstanding safety profile and the unmet flexibility of genetic vaccines.
Based on in situ protein expression, mRNA vaccines are capable of inducing a balanced immune response comprising both cellular and humoral immunity while not subject to MHC haplotype restriction. In addition, mRNA is an intrinsically safe vector as it is a minimal and only transient carrier of information that does not interact with the genome.
Because any protein can be expressed from mRNA without the need to adjust the production process, mRNA vaccines also offer maximum flexibility with respect to development.
mRNA vaccines and Covid 19:
As the Covid-19 pandemic spread, an mRNA vaccine candidate was the first to enter human trials globally.
The first two vaccines that were made available for use in the US were based on mRNA technology. Pfizer-BioNTech and Moderna used messenger RNA or mRNA to deliver a message to your immune system. Basically, the technology uses genetically engineered mRNA to instruct cells to make the S-protein found on the surface of the Covid-19 virus.
According to reports from US-based Mayo Clinic, after vaccination, the muscle cells begin making S-protein pieces and displaying them on cell surfaces. This causes the body to create antibodies. mRNA vaccines cannot cause infection with the virus that causes COVID-19 or other viruses.
Both the Pfizer-BioNTech and Moderna COVID-19 vaccines are highly effective against both symptomatic and severe COVID-19 across age groups and in diverse populations. India’s first home-grown mRNA Covid-19 vaccine — GEMCOVAC-19 — developed at Pune’s Gennova Biopharmaceuticals has got a ‘restricted emergency use’ nod for the 18-and-above age group.
The new vaccine can now be stored at the temperature of a standard medical refrigerator. The approval of the nation’s first mRNA vaccine will pave the way for the development of new-variant specific mRNA vaccines that can be used as future booster doses.
Until the COVID-19 crisis, oncology had been the major area where nanotechnology based drug carriers had been widely explored. These two mRNA-based vaccine formulations will serve as a stepping stone for future applications of nanomedicine.
These nanocarrier based vaccines highlight the importance of the nanoscale and the ability of nanoscale delivery systems to protect payloads from degradation, provide tailored biodistribution and cellular delivery.
Source: Indian Express