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The COVID-19 Vaccine Explained


Governor Kristi Noem says doses of a coronavirus vaccine could be available for South Dakota health care workers and first responders before the end of the year. But how do those vaccines work?

Vaccines save lives by teaching the human body to fight off a virus it hasn’t encountered yet. Smallpox. Polio. Measles. And soon, the virus that causes COVID-19.

Imagine a microscopic ball with spikes — by now you’ve seen illustrations of what the coronavirus looks like.

“That’s why it’s called a coronavirus,” says Dr. Shankar Kurra of Monument Health in Rapid City. “It looks like the solar corona with spikes emanating around the sphere. Those spikes are the way this virus attaches to the human cell. And that’s how it gets access into the cell. Once it gets in, it replicates. That’s an invaded cell. Now you’re infected and unfortunately bad things happen.”

In the case of COVID-19, those bad things include everything from a mild cough to a life-threatening loss of the ability to breathe. Thousands of South Dakotans have been infected. Thousands have recovered. But more than 800 South Dakotans have also died from COVID-19. With hospitals across the state struggling to meet the new surge of infected and critically ill patients, that death toll will continue to rise.

Since the moment the virus was discovered, scientists and governments around the world have been pouring billions of dollars into the development of a safe and effective vaccine.

The vaccines closest to approval are the first of their kind because instead of using a weakened or inactive version of the virus to teach the immune system how to respond, they use a blueprint of sorts. You don’t need to understand ho
w that works, but if you want to, first it helps to understand a little something about RNA.
“It’s what’s called a messenger RNA,” says Kurra. “The basic building blocks, the code for all life, is in DNA, which most of us recognize. For viruses, quite a few of them have RNA, which is just a single strand. Think of it as a DNA but with one strand missing. What this vaccine does is it takes a snippet of an RNA, which is called a messenger. It carries the message to make a specific protein, in this case the spike protein.”

And that brings us back to that ball with spikes we talked about before.

“What the vaccine does, it’s very clever. It takes just a snippet that can code for that protein,” Kurra explains. “Not the whole virus, just that spike protein. So when you inject this messenger RNA vaccine into a shoulder muscle, the RNA is then taken in by the cell and then it’s the cell’s own machinery that reads that code and makes that specific spike protein. Once it does so, the human immune system automatically goes into action. It recognizes that as alien and builds antibodies specifically targeted against the spike protein. Once that’s accomplished, the person who receives the vaccine, when they encounter or get infected, the virus is unable to attach to the human cell because it’s blocked by the specific antibodies our immune system has produced.”

South Dakotans, quite reasonably, want to know: Does this vaccine work? And … is it safe?

“This has been very successful in animal trials (pre-clinical trials.)” Kurra says. “Then phase I and phase II clinical trials showed that this is a very safe vaccine. This current phase III trial is looking at 40,000 participants in each of these two mRNA vaccines, both the Moderna vaccine and the Pfizer BioNTech vaccine). What these studies have shown is that of 40,000 volunteers, when half of them received the vaccine and half did not, all of those folks who received the vaccine received 90 to 95 percent protection against getting the disease when they were exposed to it. They were also safe. It does not cause any harm to the individuals concerned.”

A genetic code makes a protein. Which means the patient can’t actually contract anything from the vaccine itself. It’s precise and targeted protection with the potential to not only fight COVID-19, but to revolutionize the way we think about vaccination development in the future.