What is a virus?
Viruses are tiny creatures, even smaller than bacteria. They were discovered in the late 1800s. They have a simple make-up, with only a few parts. In the middle is some genetic material – like DNA. This is surrounded by a coating, called a “capsid.” Some also have an “envelope,” made of lipids (fats) that surrounds the capsid. The COVID-19 coronavirus has an envelope like this. The spiky shape is created by parts that stick out of the envelope – these attach to cells in the human body.
Every form of life can be infected by different viruses, including domestic and wild animals, and even bacteria. Some people have said the Coronavirus was a bat virus that got into humans who ate bats.
Viruses are a type of parasite – a creature that “steals” from another species to live. Viruses can’t reproduce outside of a host body, so they enter a host to live and make “babies”. In fact, viruses are mysterious creatures. Normally, a living creature can reproduce on its own or with others in the same species. Since viruses need a host cell to create “babies,” scientists don’t know if they are alive or not.
The Coronavirus Family
There are lots of types of coronavirus, but only seven affect humans. They affect the respiratory system. Four of them cause the common cold – also known as an upper respiratory infection. These mostly affect the nose and throat. So, what makes the COVID-19 virus more serious?
Along with two other members of the coronavirus family – MERS and SARS – it can cause a lower respiratory infection, which affects the lungs.
COVID-19 can also interrupt the messages between our immune cells. This can slow down our body’s immune system, giving the virus a head start before our body can defend itself.
The immune system can usually catch up to defeat the virus, so most healthy people easily survive an infection. People who have weaker immune systems or problems of the lungs and respiratory system can’t defend themselves as well. Even the common cold can cause problems for these people.
Now that you know what a virus is, stay tuned to find out how your body deals with it!