Corona go | Go corona

I'm writing this post to lay out the overall picture of what corona virus is and how our body responds to it.

In the age of fake news, it is hard to gather reliable information in one place. It is my attempt to capture certain facts and figures here and let the reader go on with their exploration with right basic info at hand.

My primary sources of information are the Newyork Times, The Hindu , articles from US National Library of Medicine, Center for disease Control and Prevention, WHO websites and articles linked there. I have referenced most of those articles down below.

First of all, some basics -

What is DNA, RNA, genes and proteins

DNA contains all the genetic information which includes one's characteristic traits, eye color, physical appearance, disposition of certain diseases etc.

This genetic information manifests as proteins in the body and define all the characteristics. The genes have the information needed to make these proteins.

DNA is like a blueprint for making these proteins. The plan to make one single protein (or sometimes one group of proteins) is called a gene. This DNA material lies in the nucleus of the cell.

Be it for growth or repair, when your cell wants to make protein, it looks up the gene information and gets the blueprint or template for that protein.

Once we have the plan, someone has to take this plan to the protein construction site called the ribosome. This someone or the scribe is called the messenger RNA(mRNA).

Whatever this mRNA carries is built by the ribosome and thus the cell would get the protein it wanted.

The journey from gene to protein is complex and tightly controlled within each cell. The above explained process takes place in 2 steps called Transcription (information copy into RNA) and Translation (Building out the protein bock by block). Amino acids are the building blocks of proteins and blueprint contains codes to make these amino acids

What is a virus? How does it affect our body?

Taken from NYT

Virus is a string of RNA information enclosed within a lipid(fat molecules) envelope.

When this envelope gets into the body, it hijacks the cell's protein making factory by supplying its RNA material to the ribosomes and creating its own copies instead, until the cell is filled with millions of viruses and explodes infecting neighboring cells.

This process will go on till the body detects an anomaly and tries attacking these diseased cells.

This brings us to the next topic - Immunity

The body stays vigilant and alerts the immune system(body's defense system) to the intruders like virus and bacteria. This action is performed by proteins called antibodies. Immune system has ability to design and refine these antibodies to fight off or neutralize specific viruses or bacteria. This process may take a week or more and both the process and the potency of the final antibodies can vary per person.

Some people make powerful neutralizing antibodies to an infection, while others mount a milder response.The antibodies generated in response to infection with some viruses — polio or measles, for example — bestow a lifetime of immunity. But antibodies to the coronaviruses that cause the common cold persist for just one to three years — and that may be true of their new cousin as well.

Another word which one should be familiar with is Antigen.

The parts of the organism which are recognized by the immune response are called antigens, and when they are recognized, an immune response is made, as either antibodies or activated immune cells that protect from disease when the same infection is seen again.

With all this information, we can now understand the idea of vaccine

A vaccine is a substance that resembles the disease-causing agent (also called pathogen) but does not cause the disease. It trains the body’s immune system to recognize and kill the pathogen, and creates a memory for the future.

Vaccines are available to protect us against many life-threatening diseases such as polio, influenza, meningitis, typhoid, tetanus, diphtheria, and certain types of cancers. Vaccines have also been responsible for eradication (or near eradication) of deadly diseases such as smallpox and polio.

Different vaccines for COVID-19

40 different candidate vaccines for COVID-19 are in development. These include

an inactivated vaccine being developed in China (Sinovac) using purified COVID-19 virus killed with formaldehyde (a chemical).
A live attenuated vaccine being developed by Codagenix, a U.S.-based company in partnership with the Serum Institute of India (Pune), uses a genetically engineered COVID-19 virus that replicates very poorly.
There are multiple other vaccine candidates under development that use DNA, RNA, viral vector and subunit protein platforms.

mRNA vaccine (The one in Phase-1 trials already)

The mRNA-1273 is a piece of RNA that carries the code to make the COVID-19 virus Spike protein when introduced into cells.
This protein present on the virus surface is critical for its entry into cells.

Immunity (antibodies) to the Spike protein can block virus entry and its multiplication, and thus ameliorate the disease.

Once inside a cell, the mRNA instructs the cell to produce the antigen, which is now recognized by the immune system which makes an antibody or cellular response.

This vaccine is currently in Phase-1 clinical trial in Seattle(March 17)

Developed in partnership with the Vaccine Research Center at the National Institutes of Health (NIH) and their collaborators at the biotechnology company Moderna, Inc. based in Cambridge, Massachusetts, U.S.

The COVID-19 vaccine has been fast-tracked into humans without prior testing in animals. Still, it may take one to two years for the clinical trials to be over.

To understand the timelines involved in vaccine development, it is important to understand the process

Phases in Vaccine development

Pre-clinical development - Vaccine produces antigens(a toxin or other foreign substance which induces an immune response in the body) to stimulate human immune system to generate antibodies
Candidate Vaccine - Tested on animals
Phase 1 - Evaluate vaccine safety and ability to generate immune system response in a small group of volunteers
Phase 2 - Several hundred volunteers, including groups at risk
Phase 3 - Large scale trials - natural disease conditions : If successful, maker applies for license to market the vaccine
Phase 4 - Large scale industry production, Quality control - rare adverse reaction study

Now for some fun!

https://www.youtube.com/watch?v=9ToEfjE48Dw