What Is a COVID-19 Variant?
Viruses are always changing, and that can cause a new variant, or strain, of a virus to form. A variant usually doesn’t affect how the virus works. But sometimes they make it act in different ways.
Scientists around the world are tracking changes in the virus that causes COVID-19. Their research is helping experts understand whether certain COVID-19 variants spread faster than others, how they might affect your health, and how effective different vaccines might be against them.
How Many Coronaviruses Are There?
Coronaviruses didn’t just pop up recently. They’re a large family of viruses that have been around for a long time. Many of them can cause a variety of illnesses, from a mild cough to severe respiratory illnesses.
The new (or “novel”) coronavirus that causes COVID-19 is one of several known to infect humans. It’s probably been around for some time in animals. Sometimes, a virus in animals crosses over into people. That’s what scientists think happened here. So this virus isn’t new to the world, but it is new to humans. When scientists found out that it was making people sick in 2019, they named it as a novel coronavirus. Experts call these strains SARS-CoV-2.
How Do Variants Happen?
Coronaviruses have all their genetic material in something called RNA (ribonucleic acid). RNA has some similarities to DNA, but they aren’t the same.
When viruses infect you, they attach to your cells, get inside them, and make copies of their RNA, which helps them spread. If there’s a copying mistake, the RNA gets changed. Scientists call those changes mutations.
These changes happen randomly and by accident. It’s a normal part of what happens to viruses as they multiply and spread.
Because the changes are random, they may make little to no difference in a person’s health. Other times, they may cause disease. For example, one reason you need a flu shot every year is because influenza viruses change from year to year. This year’s flu virus probably isn’t the exact same one that circulated last year.
If a virus has a random change that makes it easier to infect people and it spreads, that variant will become more common.
The bottom line is that all viruses, including coronaviruses, can change over time.