To answer the question
1. Why Are Covid-19 Vaccines Causing Severe Side Effects?
we must first answer the question
2. How does the Covid-19 virus cause so much harm?

The answer to the second question is that the virus causes its harm mainly by means of its spike protein. The virus is spherical, with a bilipid membrane, similar to the cell membrane in human cells. The membrane is covered with hundreds of protein Spikes. Usually, when you see a drawing or illustration of the virus, they show a few dozen Spikes. But, no, there are actually hundreds of them. These Spikes cause much of the harm resulting from the virus — not all the harm, but a good portion of it. Without spikes, a Covid-19 virus would be nearly harmless.

All these Covid-19 Vaccines cause your body’s cells to make the viral Spike proteins and display them on the surface of your body’s cells. This is what causes the immune system to make antibodies. It sees these Spikes that are not supposed to be there, recognizes them as foreign, and makes the antibodies. Great.

But the number of cells making these Spikes and the number of Spikes can be very high. Apparently, the vaccine injection can cause the vaccine to travel to remote places in the body, making Spikes in places where they should not be: the lining of blood vessels, nerve cells, brain cells and so on. And for the mRNA vaccines, how long does the mRNA remain in your system, causing cells to make these Spikes? In some cases longer than in other cases.

What happens when ordinary cells of the human body now have the Spikes from the Covid-19 sticking out all over the cell membrane? Bad side effects, apparently. There have even been cases of person who receive the vaccine ending up with LongCovid-like symptoms for weeks or months.

Some elderly persons have died from the vaccine. Some pregnant women have miscarried. Some persons have ended up with Bell’s Palsy or even an appendicitis. There is a wide range of severe side effects from this vaccine.

The Vaccine makers made a mistake in choosing to have the vaccines cause the body to make Spikes to be displayed in the cell membranes of cells in the human body. They should have used a simple “killed virus” vaccine, where you take the Covid-19 virus, and kill it, and then inject it. Then the Spikes remain in the virus, and never are produced by a human cell, and never become part of that human cell.