Doug Durno August’20

Viruses – Foe and Friend

By Doug Durno

Viruses are bad. We all know that. I mean just look at the coronavirus. As well, viruses cause influenza, pneumonia, HIV, herpes, hepatitis, colds, rabies and many other diseases. So, maybe you’re thinking it would be wonderful if viruses could be made to disappear. Not so fast. As epidemiologist Tony Goldberg put it, “If all viruses suddenly disappeared, the world would be a wonderful place for about a day and a half, and then we’d all die. All the essential things viruses do in the world far outweigh the bad things.”

Well, if viruses are doing such awesome things for us, why haven’t we heard about them? Mainly because scientists are always busy trying to find remedies for the various viral diseases. It wasn’t until the 1990s that research on the positive side of viruses really got going. But, before we look at some of those benefits, let’s learn a little about viruses.

Viruses live to infect. They infect to reproduce. That’s it.

So it won’t surprise you that viruses are simple things. They’re just genetic material (either RNA or DNA) contained in a protein shell, with some having a fatty membrane enveloping them.

Coronavirus is one of those viruses with that fatty membrane shielding its innards. Soap can destroy fatty things. So it can bust that membrane apart. Hand sanitizer is almost as good. But it should be at least 60% alcohol. That means beer (5%) and wine (12%) are useless for disinfecting.

Since they lack a cellular structure, viruses can’t use cell division to reproduce. Instead, they inject themselves into a host cell – be it animal, plant, fungus or bacteria. Once inside, the virus releases its genetic material, which then hijacks its host cell and commands it to assemble copies of the virus. Hundreds of new viruses can be made each time this happens. That’s why the coronavirus can spread so quickly through the body.

Viruses are found almost everywhere on Earth. Way smaller than bacteria, they’re abundant to say the least. Oceanographer Jennifer Brum said that if you took a swig of seawater while swimming in the ocean, you’d have 200 million viruses in your mouth. And those viruses are going to be infecting the 20 million bacteria in that same mouthful. Not to worry though, most viruses and bacteria are harmless.

Now let’s get a sampling of the beneficial things viruses do:

Stayin’ Alive

We all know that we depend on plants for our oxygen. Except that’s only half true. Plants supply only about 50%. The other 50% comes from the oceans, specifically from microscopic phytoplankton. These microbes produce energy through photosynthesis, and release oxygen as a waste product. Now what if these phytoplankton were to die off for some reason. Well, we’d soon die off too. In actuality, phytoplankton are always in danger. And it’s viruses that save them. When viruses kill the bacteria that host them, nutrients are released that phytoplankton can then ingest, ensuring they’re able to keep pumping out that oxygen we require. Viruses kill up to 50% of all oceanic bacteria – every day.

Kill the Winner

= Biodiversity – Sometimes a species, be it insect or bacteria, will be too successful, outcompeting others in its ecosystem. Logically, this should lead to the ‘winner’ forcing its competitors out. Fortunately, viruses multiply right along with their ‘winner’ host, keeping it in check. Thus space is kept open for biodiversity to be maintained. Perhaps with tongue in cheek, some describe the coronavirus as a “kill the winner” event.

Antibiotic Resistance

The more we use antibiotics, the greater the chance that bacteria will develop resistance. One alternative is the bioengineering of viruses to target a specific infection. As someone put it, they’re “like little microscopic guided missiles that go in and blow up the cells we don’t want”. This way, unlike antibiotics, the beneficial bacteria in our systems are left alone. When used against cancer cells, there are no side effects.

This list could go on and on. But the point is made with these few: viruses help to maintain life, balance and diversity on Earth. So, although we always have to be wary, we should also appreciate viruses for what they provide.