As the COVID-19 pandemic evolved, we heard about “variants” of the virus that were different from the original one that started the pandemic. Here are the basics on variants.

What Is a Variant?

When viruses spread, they make copies of themselves. As they do, they often mutate, or change, a little bit. A copy that is different from the original virus is called a variant. Sometimes variants don’t seem that different from the original virus. Others may have clear differences.

The coronavirus that causes COVID-19 has gone through this type of changing process many times during the pandemic. Each time a new coronavirus variant emerges, the World Health Organization (WHO) gives it a name based on a letter from the Greek alphabet. Variants of note include alpha, delta, and omicron.

How Can Variants Differ From the Original Virus?

Variants can differ from the original virus based on:

• how contagious they are
• how sick they make people
• how they respond to vaccines and medicines
• whether people can get infected with the virus more than once

What Can Protect People From These Variants?

In general, the steps that experts have recommended to protect us from the original virus also can work to stop the spread of other variants.

It is still very important to keep doing the things that are in our control, such as:

• staying up to date with COVID-19 vaccines
• washing hands well and often
  
• testing and staying home when necessary
• making sure indoor spaces are well-ventilated

What Else Should I Know?

Everyone 6 months of age or older should get an updated COVID-19 vaccine this 2023–24 season. The updated vaccine protects against the variants that are now most common.