A refresher on viruses

A refresher on viruses


January 27, 2020 

Just What is a Virus?

The names are part of the common language now: Ebola, Sars, Bird Flu, Swine Flu, Influenza. And with the dawn of a new year, you can add a new name: coronavirus. Viruses caused all of those diseases. Some are more serious than others but as we have seen over time, viruses are part of life.

So just what is a virus? The irony is that while viruses “live”, they aren’t technically alive. Viruses are microscopic parasites that lack the ability to thrive and reproduce outside of a host body. That’s right, viruses can only replicate inside the cells of their host. A host can be an animal, a human, a plant bacterium or even a fungus. It’s also ironic that viruses carry all of the elements that make up a living organism: DNA, RNA, nucleic acids. But as mentioned, viruses can’t do anything with the genetic codes they carry.

Think of a virus as simply a delivery system. It’s a package in a covering of protein. When the virus attaches itself to a cell and infects the cell, it delivers the genetic code with a simple message, “Make more viruses!” After the virus attacks and hijacks the cell, the host cell dies, spewing new viruses to attack more cells. That cascading effect makes it perfect for creating conditions that allow for the virus to spread. It also explains why a person with a viral infection (even the common cold) feels badly for several days. That’s the virus spreading and the body’s immune system fighting the spread. Yep, your body is a battleground!

Now think of that person sneezing. There goes up to 40,000 droplets containing viruses into the air. Depending on the conditions, those viruses can stay alive for a couple of hours. Breathing in those droplets or touching the droplet and then touching your eye or mouth, spreads the virus and the cycle starts again in a new host.

How to prevent a virus

Wash your hands! Cover your mouth when you sneeze or cough! There’s a good reason for all those lessons parents teach. It’s also why you see photos of people wearing masks in countries with outbreaks of viruses. For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus.

There are some antiviral medicines to treat some infections. They primarily block the virus as it attempts to copy itself or block the virus from invading the host cell. Antibiotics don’t work on viruses. For most viruses, the best defense is a good offense. Stay healthy, follow your parent’s advice listed above. That’s also why vaccines are important. They help the body protect itself by boosting the immune system.

—Frank Graff 

 Frank Graff is a producer/reporter with UNC-TV, focusing on Sci NC, a broadcast and online science series.