By Aayat Iftikhar, age 9
Viruses are invisible killers that can cause sicknesses like polio, influenza, chickenpox, mpox, COVID, the common cold, fever, and more. They are invisible to the naked eye. For example, the polio virus is 10,000 times smaller than a grain of salt, according to PBS.
When scientists first discovered viruses, they could not even see them. Then, in 1931, the electron microscope was invented. This amazing tool allowed scientists to see all the complex forms of viruses.
Viruses have different shapes, like spheres, rods, and bullets. They are made from nucleic acid, which is a protein. They have spikes on their protein shell called capsid, and some have a greasy outer coating, according to PBS.
Some viruses travel through air to the nose or mouth. Some enter through body fluids or breaks in the skin. You can also get a virus, like dengue, from a mosquito or a bug bite.
As Encyclopedia Britannica Kids says, “On its own, a virus is lifeless. However, it becomes active when it infects, or enters, a cell of an animal or a plant.”
A virus needs a host, or a living thing—like you and me!—to multiply. A virus uses the spikes on its outer shell to attach to the host’s cell wall, then it gets in and uses the cell to make copies of itself. That is so sneaky!
As Encyclopedia Britannica Kids puts it, “A virus reproduces itself by taking over a living cell and making it into a virus factory.”
When a virus enters the body, special cells of the body’s immune system become active and fight the virus by producing antibodies. A fever is one of the signs that shows that your body is fighting against a virus. Once your body fights a virus, it creates immunity to protect you for the next time.
You can prevent viruses by covering your mouth and nose when you sneeze, washing your hands for 20 seconds, and keeping your vaccination schedule up to date when your doctor tells you to. A vaccine is a version of the virus that will not make you sick but teaches your immune system to protect your body.
When you’re sick, stay away from other people to avoid spreading the virus. You should also wear a mask.
Today, scientists believe there are 10 to the 31st power viruses on Earth—that’s 10 with 30 zeros!
