Teddies Talks Biology - Issue 9

Continued

What is mRNA and how is it useful as a vaccine?

Messenger RNA, shortened to mRNA, has a structure similar to DNA, however they are not the same. The role of mes- senger RNA is to form a copy of the ba-

ses on one of the two strands of a DNA molecule in a process known as transcription. This all happens in the nucleus; the mRNA then leaves the nucleus and serves as instructions for the synthesis of proteins in the cytoplasm. As previously mentioned, most vaccines today are made up a weakened pathogens or parts of one which give us active immunity, mRNA vaccines provide immunity in a slightly different way. These vaccines contain mRNA with the necessary genetic information to make bits of these viral proteins, which triggers an immune response and provides active immunity. Exam- ples of mRNA vaccines include the Pfizer and Moderna, which are two of the most recent Covid vaccines. mRNA vaccine technology is not a new feat however, due to its single - stranded structure mRNA is a fragile molecule that is difficult to deliver to our cells. The issue of their stability has been overcome much more quickly due to the urgent need for a Covid vac- cine.

Conventional vaccines

mRNA vaccines

Most vaccines against viral diseases are made from viruses grown in mam- mal cells. The process of extracting, adapting, and shipping them can take months, which is problematic if there is immediate demand for the vac- cine. There are hazards associated with growing large batches of virus, such as contamination.

The RNA is made from a template in a lab from an electronic sequence that can be sent across the world instantly by computer. It takes roughly a week to produce an experimental batch of mRNA vaccines.

Production time

Only small quantities of virus are needed for gene sequencing and testing the vaccine.

Biosafety

Immune response The antigen is injected into the body. As soon as the body recognises it as a non - self - cell, the immune system pro- duces specific antibodies to neutralise it.

RNA enters the cells where it provides instructions to produce antigens. The body then recognises the antigens and produces antibodies to fight them.

Teddies Talks Biology I Issue 9 I June 2021

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