The COVID-19 vaccines are safe. Here’s why.

Aadil Kamran
4 min readDec 23, 2020

Pfizer and Moderna have both created a vaccine for COVID-19. However, many are afraid of the side effects. Some even believe the vaccine will change their DNA. There is no reason to be afraid of the vaccine, and anyone telling you otherwise is lying to you.

In order to know how the vaccine works, we must understand how our cells and how viruses work. DNA contains the information cells need so that they can do their jobs in our body. DNA is like a cookbook which contains all the recipes you may need. In order to do these jobs, the cell makes proteins. DNA contains the instructions to create these proteins, so it makes copies of the instructions in the form of RNA.

RNA is very similar to DNA, but it is made up of slightly different building blocks than DNA. Just as DNA is the cookbook, RNA is a picture of a recipe in the cookbook that you can send to others. These instructions in the form of RNA go to ribosomes, which are the “factories” that make the proteins. This makes the RNA a “message” from DNA to the ribosomes, which is why this kind of RNA is called messenger RNA or mRNA.

The COVID-19 virus is made up of RNA enclosed in a protein coat. The protein coat protects the RNA and helps it get inside a living cell. Once inside, the virus tries to hijack the ribosomes so that it can create more of itself. Because the RNA of the virus is made up of the same basic units as our mRNA, it can go directly to the ribosomes to make the viral proteins.

Along with the protein coat, the viral RNA also has instructions for making a protein called RNA polymerase. This protein allows the RNA to replicate itself. Once many copies of the viral RNA and protein coat are made, they assemble themselves into the viruses and break out of the cell. The cell dies and the viruses go to infect nearby cells.

Some of our cells are designed to recognize that a virus has infected our body. They see that a viral protein is being created in infected cells. They “show” this protein to immune cells, which prepare other immune cells to destroy anything that comes into the body with that specific protein.

The two vaccines are mRNA vaccines. This means they contain a small part of the COVID-19 RNA which is recognized by our cells as mRNA. The part they contain is only the part that makes the spike protein in the protein coat. This spike protein helps the virus enter our cells, but it’s harmless on its own.

By having the mRNA, our cells can create the spike protein. Immune cells can then see that this spike protein is not ours. If COVID-19 enters the body, our immune cells will destroy the virus by recognizing the spike protein.

When mRNA is made, it is sent out into ribosomes and is not “allowed” back into the nucleus where DNA is located. The nucleus is protected by nuclear pores, which act as “gatekeepers.” If a vaccine puts new mRNA into our cells, this new mRNA will go to the ribosomes as well. It won’t have “clearance” to go to the nucleus. This is why our genes cannot be changed by an mRNA vaccine.

There will be side-effects to taking the vaccine. According to the CDC, these may include fever, chills, tiredness, and headaches. Our body’s response to a new illness is like that of a good student entering a hard class. At first, the student has no idea what to expect, so he or she has to figure out the best way to study. Once the student has taken an exam, the class becomes easier because the student knows how to study for the class and do well.

Likewise, the body tries many different ways to best destroy a new viral protein. Different immune cells are made, and the ones which are best suited to destroy the virus are kept. They are then stored in “memory.” In “learning” how to fight the virus, the immune system overreacts, which causes the side effects.

If COVID-19 enters the body, the body will make the immune cells it has in its “memory” for COVID-19. This is why you feel less sick the second time you get an illness. The truth is that COVID-19 does much more damage and is more unpleasant than any of the side effects of the vaccine.

Vials of the COVID-19 vaccine are seen at Walter Reed National Military Medical Center, Bethesda, Md., Dec. 14, 2020. (DoD photo by Lisa Ferdinando)



Aadil Kamran

Aadil Kamran is senior pre-med student studying biology at Loyola University Chicago