mRNA and it’s working

Subject :Science and Technology

Section :Biotechnology

Context:

The country’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.

mRNA working:

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.
Unlike vaccines that put a weakened or inactivated virus in our body to activate an immune response, these two Covid-19 vaccines (Pfizer-BioNTech and Moderna) used messenger RNA or mRNA to deliver a message to our 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.
But these vaccines have to be stored at sub-zero temperatures as mRNA is fragile and breaks down easily.

Thermostable vaccine

“Unlike in the West, where the vaccine has to be stored at sub-zero temperatures, the challenge in India was to be able to store the vaccine between 2-8 degree Celsius.
Gennova had to innovate to suit Indian local needs as to what is affordable and deployable. GEMCOVAC-19 can now be stored at the temperature of a standard medical refrigerator.
However, just removing water by Lyophilisation of the mRNA vaccine does not work. So, the surrounding pressure has to be tweaked and then kept stable to ensure the characteristics of the vaccine are the same as before Lyophilisation.
For this to be achieved, the key was to add an external agent which at a certain critical concentration keeps it stable under lyophilized conditions. The Lyophilisation technology is not new, but a lyophilized mRNA vaccine is unique.