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How does a COVID-19 vaccine work within the physique? – Wixy, age 12, New York
The COVID-19 pandemic, brought on by the SARS-CoV-2 virus, has modified the way in which individuals reside world wide. As of late August 2021, greater than 630,000 individuals have died in the US alone. Well being specialists agree that COVID-19 vaccines are one vital means to assist convey an finish to the pandemic.
However getting a vaccine could be scary for each youngsters and adults. Plus, there’s lot of details about how the COVID-19 vaccines work, however a few of it may be exhausting to grasp.
As a pediatrician, infectious illness physician and scientist who research germs like micro organism and viruses, I’ve devoted shut consideration to the pandemic and the event of the COVID-19 vaccines.
Vaccines are made to resemble invaders
Crucial factor to grasp about vaccines is that they train your physique the best way to gear as much as battle an an infection, with out your physique having to take care of the an infection itself. On this means, vaccines assist your physique be ready for invasions by germs that would in any other case make you very sick.
All three of the COVID-19 vaccines accessible within the U.S. give attention to what known as the spike protein of the SARS-CoV-2 virus, or coronavirus. SARS-CoV-2 is a spherical virus, with bumps throughout it – type of like a baseball lined in golf tees. The bumps are the spike proteins.
On an precise coronavirus, spike proteins enable the COVID-19 virus to get into cells so the virus could make extra copies of itself. It does this by sticking to sure sorts of proteins, known as receptors, on human cells – significantly lung cells. On this means, the virus can break into wholesome cells and infect them.
The Pfizer-BioNTech, Moderna and Johnson & Johnson vaccines all work equally by giving the physique’s cells the directions to make the spike protein. The Pfizer and Moderna vaccines carry these directions on a molecule known as mRNA. This single-stranded molecule seems to be like a protracted piece of tape with the directions to make a protein coded on one facet.
The Johnson & Johnson vaccine, alternatively, passes the directions to cells by way of DNA molecules. It makes use of a virus known as an adenovirus, which can not make copies of itself, to hold the spike proteins’ DNA into human cells. This DNA will get copied into mRNA, which then interprets the directions into proteins – on this case, the spike protein of the coronavirus.
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So the principle distinction between the three vaccines is that the Pfizer and Moderna pictures give your physique directions for the spike protein by way of mRNA, whereas the Johnson & Johnson shot directs it by way of DNA. After that, all three vaccines work the identical means.
What occurs when the vaccine enters your physique?
As soon as a COVID-19 vaccine is injected, the mRNA or DNA will get swallowed up by tissue cells and particular immune cells that reside in muscular tissues, pores and skin and organs known as dendritic cells. Dendritic cells hold watch over all elements of the physique like sentinels, trying to find indicators of invading germs – just like the coronavirus.
As quickly because the DNA or mRNA is contained in the dendritic or tissue cells, the cells use the directions to create spike proteins. This course of normally takes lower than 12 hours. After the spike proteins are made and able to “present” to the immune system, the mRNA or DNA is damaged down by the cell and eradicated.
It’s vital to know that despite the fact that your cells have made their very own spike proteins, they don’t have sufficient info to make copies of the complete virus. However the spike proteins can set off the physique’s immune system to amp up its protection so it’s prepared if the entire coronavirus invades.
When the tissue cells and dendritic cells acknowledge the spike proteins as unwelcome guests, the cells place sections of the spike proteins on their exterior for different cells to see. The dendritic cells additionally launch “hazard” alerts on the identical time to let different cells know that the spike protein presents a menace. The hazard alerts are like flashing neon yellow indicators pointing to the displayed spike protein piece saying, “This doesn’t belong!”
These warning alerts then fireplace up your physique’s immune response.
What occurs as soon as the immune system will get revved up?
Due to that course of, the physique is now on excessive alert and able to be taught to battle invaders – on this case, the spike proteins made after injection with the COVID-19 vaccine.
Immune cells within the physique, known as B-cells and T-cells, acknowledge the warning indicators of an outdoor invader. 1000’s of those cells rush to the realm to study this new menace to allow them to assist present safety.
B-cells are specialists at constructing “traps,” known as antibodies, that can take down any invading spike proteins. Totally different B-cells make plenty of specialised antibodies that acknowledge totally different elements of a virus or micro organism. And B-cells will act like a manufacturing facility, persevering with to make antibodies towards the perceived menace even after it’s gone so as to defend the physique for a very long time to return.
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One sort of T-cell, known as helper T-cells, help the B-cells in making antibodies when hazard alerts are current. One other type of T-cell is there to verify if different cells within the physique are contaminated by the virus. If that sort of T-cell spots an contaminated cell, it removes the contaminated cell so it can not create extra copies and move on the an infection to different cells.
Why is my arm sore?
As all of those vital processes are taking place inside your physique, you would possibly see some bodily indicators that there’s a battle occurring beneath the pores and skin. In case your arm will get sore after you get the shot, it’s as a result of immune cells just like the dendritic cells, T-cells and B-cells are racing to the arm to examine the menace.
You may also expertise a fever or different indicators of illness. All of those imply that your physique is doing precisely what it’s speculated to. It is a protected and pure course of that occurs when the physique is studying the best way to battle the spike proteins. That means, when you do come into contact with the true coronavirus, your physique has realized the best way to defend you from it.
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