We have vaccines against COVID-19, but not everyone is racing to the clinic. Because the vaccines are new, some people are hesitant. They want more information.
Your immune system is truly amazing! It protects you from harmful substances like bacteria, viruses, fungi, parasites and cancer cells. It works by finding and eliminating bad substances. There’s a “basic” immune system that’s the same for everyone. It recognizes foreign cells and either kills or “eats” them.
But the more specialized and powerful immune system, AKA the “adaptive” immune system, learns by experience. Once it’s encountered a certain substance that seems harmful (an infection), it “remembers” something about it and makes specialized cells to fight it. Those special cells are called antibodies. Vaccines make you make antibodies.
All vaccines trick your immune system into protecting you from an infection you’ve never actually had. How? The first method, used by Jenner in 1796, used an actual live virus! Cowpox, a live virus related to smallpox, produced immunity from the deadly smallpox virus.
The next vaccines used killed viruses, like Salk’s poliovirus vaccine in 1954. The entire “dead” poliovirus was used. The immune system nevertheless recognized it and produced antibodies. The third step used a live virus that had been subtly changed, so while immune cells could still “see” it as an invader, it couldn’t cause harm. That was also effective, and Sabin used that technique in the early 1960s to make an improved poliovirus vaccine. This vaccine remains the main tool in the fight against polio worldwide.
Today, medical technology is really shaking up the world of vaccine making. New and better ways to trick and boost the immune system are being developed at an ever-increasing rate. The invention of recombinant DNA and genetic engineering kick-started things soon after a way to decode or “sequence” the DNA molecule was discovered.
In 1986 the first recombinant vaccine, for Hepatitis B, was made. The part of the virus that causes an immune reaction was spliced into yeast cells to grow more bits of that small part of the gene. By injecting only that tiny part, rather than an entire virus, the vaccine was able to do its work to make the body produce antibodies. Increasingly, there are more and better ways to produce vaccine immunity without ever inserting a harmful virus, living, dead, or altered, into your body.
One new technology being used in two of the COVID-19 vaccines is mRNA. Messenger RNA is found in every living organism as a tool for building proteins. It acts like a boss giving orders. Once a cell is told to make a protein by mRNA, the mRNA itself is quickly broken down and eliminated. It doesn’t enter the cell nucleus and cannot change DNA. That’s important to know, because one thing folks are a bit anxious about is a fear that it (the vaccine) will alter their DNA. It cannot.
Why use it? Because mRNA can be made to carry the blueprint of the spike protein part of the SARS-CoV-2 virus that causes COVID-19. Without that spike protein, the virus couldn’t attach to your cells. You couldn’t be infected. Which is exactly the idea. It tells your own cells to make the protein. Then your body develops antibodies to the protein, and you’re immunized! It’s a neat trick, and it doesn’t introduce any whole virus into your system. And it can’t alter your DNA. The Moderna and the Pfizer vaccines both use mRNA technology.
The only other COVID-19 vaccine authorized by the FDA is the one made by Johnson & Johnson (J&J). It doesn’t use mRNA, it uses a gene-editing technique. It delivers blueprints to make the spike protein to your cells via a disabled common cold virus.
Before being disabled, the cold virus is “spliced” to include the code for the spike protein. When the disabled cold virus is injected, it bumps into cells and attaches to them like any other cold virus. Then it makes its way into the cell nucleus where it delivers the orders to replicate. Same trick, different method.
Your body now makes spike proteins, and the immune system does its work. This vaccine also creates a strong immune reaction without delivering the actual COVID-19 virus. It also can’t change your DNA. Unlike the previously described vaccines, the J&J brand requires only one shot, not two.
We have three vaccines available here in the United States. The FDA has found all three to be safe and effective enough for Emergency Use Authorization. Pfizer has recently applied for full FDA approval, which will likely be granted. The other two will soon follow suit.
You can get the Moderna shot at most local pharmacies and the Walmart pharmacy in Berryville. The Pfizer vaccine is being given at Eureka Springs Hospital and the Carroll County Health Unit in Berryville. The Carroll County Health Unit also has a supply of the J&J vaccine, but so far has not distributed any because of insufficient demand. Once enough people are signed up, they will open begin offering that option. To learn more about FDA-authorized vaccines, visit the CDC website.