When we get sick, it is often because a microbe – like bacteria or a virus – has entered our body. With the COVID-19 pandemic impacting millions of people around the world, we have seen the effect a virus can have on society – but what is a virus, anyway? Here at LN Gen Z, we thought it was time to take some of the mystery out of the Coronavirus, and figure out exactly what’s going on in our bodies.
What is a virus?
Viruses are microscopic creatures, even smaller than bacteria. They are a relatively recent discovery. Mankind first became aware of them in 1892, when the Russian botanist Dmitri Ivanovsky was looking for the reason that diseased tobacco plants remained infected even when bacteria were filtered out – the culprit was tobacco mosaic virus. In 1898, Dutch botanist Martinus Beijerinck termed the infectious substance a “virus,” and just a few decades later, in the early 20th century, many viruses had been discovered and viewed under microscopes.
Viruses have an extremely simple make-up. They consist of only a few parts. In the middle is some genetic material – DNA or RNA. This is surrounded by a protein coating, called a “capsid.” For simple viruses, that can be it. Some also have an added “envelope,” made of lipids (fats) that surrounds the capsid. The COVID-19 coronavirus has an envelope like this. The spiky shape of Coronavirus is created by some added proteins that stick out of the envelope – these attach to cells in the human body.
The first known viruses infected plants, and many don’t infect humans at all. Every form of life can be infected by different viruses, including domestic and wild animals, and even bacteria. It has been speculated that this new coronavirus was originally a bat virus that got transferred to humans who ate bats.
Is a Virus Alive?
Viruses are a type of parasite. They can’t reproduce outside of a host body, so they can only make new generations by piggybacking on a host’s cells’ ability to replicate. In fact, viruses are mysterious creatures – scientists aren’t really sure whether they are alive or not. Normally, one sign that an organism is living is that it can reproduce on its own or with others of its species. Since viruses need a host cell to create “babies,” they seem to be a cross between a chemical substance and a biological organism – or “organisms at the edge of life.”
The Coronavirus Family
There are lots of varieties of coronavirus, but only seven affect humans. Four of them (called 229E, NL63, OC43, and HKU1) cause the common cold – also known as an upper respiratory infection. These mostly affect the nose, throat, and sinuses. So, what makes SARS‑CoV‑2, the virus responsible for COVID-19, more serious?
This new Coronavirus, as well as two other members of the coronavirus family – MERS and SARS – can also cause a lower respiratory infection, which affects the lungs.
Additionally, it has the ability to disrupt the chemical messages between our immune cells. This can lead to delays in our body’s immune response, giving the infection a head start before our immune system can mount a defense.
The immune system can usually catch up to defeat SARS‑CoV‑2, which is why most healthy people survive infection without it becoming life-threatening. People who have weakened immune systems or those with existing problems of the lungs and respiratory system are less able to defend themselves. Even the common cold and flu can pose serious problems to these people, however.
You may have heard COVID-19 compared to the flu – that’s because the influenza virus also infects the respiratory cells and is usually not serious except in people who are already compromised.
Now that you know what a virus is, stay tuned to find out how your body deals with it!