The Coronavirus has a lot of people worried. It’s easy to get scared, but our bodies have a system to fight germs like the virus. It’s called the immune system. Our immune system works hard to keep us healthy – but how does it work?
It’s not easy for a virus to infect us. Human bodies have lines of defense to stop germs. Physical barriers like skin and nose hairs protect our inner parts. Chemicals in saliva and stomach acid can kill germs, too.
A virus doesn’t just infect us by touching our bodies – it has to reach the right human cells. Different viruses match different human cells. For example, the Ebola virus joins to cells in the blood and liver, and the HIV virus joins to white blood cells. The Coronavirus infects our respiratory system (mouth, nose, throat, and lungs). We can’t get infected unless it touches those cells.
The Immune System
We also have macrophages – a type of immune cell that roams around our body looking for germs to eat. If a virus or bacteria gets in, our macrophages start fighting them. If there are too many germs, our immune system sends thousands more cells to help kill them. Our body makes special chemicals called antibodies to fight the infection. It takes time for the body to make the perfect antibody to kill the virus. This is when we feel symptoms, like a fever or headache.
If the antibodies kill the germs, we get better. After that, your body knows how to deal with that virus. If you catch the same virus again, your body remembers how to make the right antibody – easy!
There’s a catch, though. A virus is always looking for ways to evade our immune cells. That’s how a virus mutates – it changes to outsmart our immune system. This creates a different strain of the virus. Then our bodies have to start again and learn how to fight the new strain.
Luckily, the Coronavirus doesn’t pose a big problem to the human immune system, so most people who catch it recover. The main people who need to be careful are those with weakened immune or respiratory systems.