COVID-19 Variants: What You Need to Know About the Latest Mutations

Published on: Dec 3, 2021fb-roundtwitter-roundemail-round
A healthcare worker fills a syringe with Pfizer Covid-19 vaccine at a community vaccination event in California.Getty Images

More than half of the US population is now fully vaxxed. And about 20% have gotten their COVID-19 booster shot. But as the world learned with Delta, variants can cause a major hitch in medical care and treatments, travel, and even the reopening of economies.

While US vaccination rates increased because of the Delta variant, it also ushered in a new wave of COVID-19 infections. And now with Omicron’s rise, Americans are seeing how quickly the virus’s variants are mutating. And becoming more transmissible. 

What are variants?

Variants happen when a virus’s genes change or mutate. The word ‘mutate’ might sound scary, but it’s actually normal. As the virus spreads, it makes copies of itself. And sometimes, not all of the same instructions make it into the new copy. So it becomes a different version (aka a new strain or variant). Typically mutations aren’t a big deal because they don’t always change how a virus behaves. 

Enter: the Omicron variant. Aka B11529. It carries a high number of mutations (think: 50). And it’s the latest variant to fall under the CDC’s list of “variants of concern.” But there’s still a lot of info we don’t know yet. Like: how it may affect treatments and vaccines, or how transmissible or dangerous it is. And details likely won’t come out until mid-December. But for now, there are some things we know for sure: 

But remember: Variants are normal. And while health experts urge caution, including getting back to the basics (think: wash your hands, mask up), there’s not enough data to spell out how Omicron could affect the ongoing pandemic response. So stay tuned.

Another variant that’s gotten a lot of attention: Delta. It was first detected in October 2020 in India. And contributed to the devastating surge of infections there earlier this year. Now, it’s the dominant strain in the US — accounting for 99% of new cases. It’s also been reported in at least 135 countries. The World Health Organization has called it “the most transmissible of the variants identified so far.” (Reminder: That could change as we learn more about Omicron.) And the CDC has labeled it a “variant of concern.”

The good news? Experts say that the vaccines available in the US are believed to be highly effective against many variants. Important, because in September, the CDC reported that unvaccinated people were 14 times more likely to die from COVID-19 in comparison to vaccinated people. But more good news: In the US, vaccines are available for people five years old and up.

What other variants do I need to know about?

The World Health Organization has labeled three other “variants of concern,” including…   

  • Alpha. Aka B117. It was first detected in September 2020 in the UK. It’s spread to at least 182 countries. And was previously the dominant strain in the US earlier this year. The CDC says it’s believed to be about 50% more contagious and could potentially cause more severe illness. Experts say that the vaccines currently available seem to offer good protection against the alpha variant.

  • Beta. Aka B1351. It first emerged in October 2020 in South Africa. And has spread to at least 131 countries. It’s been found to be about 50% more transmissible, and there are concerns that vaccines may not be as effective when it comes to this variant. Researchers have found that it includes mutations that may make it easier for it to evade antibodies.

  • Gamma. Aka P1. This variant was detected in January 2022 after four travelers went from Brazil to Japan. The WHO says it’s been found in at least 81 countries. It helped fuel a surge of cases in Brazil in late 2020 and quickly spread to other areas of South America. Similar to the Beta variant, Gamma has mutations that the Mayo Clinic says may help it evade antibodies generated by a COVID-19 infection or vaccine.


The US is in a critical period of combating the coronavirus as it deals with the potential of a winter surge and dangerous variants. As scientists continue to detect new variants and learn more about existing ones, it’s still as important as ever to keep practicing the basics — whether or not you got your shots.

Last updated on Dec 3 to include details about the Omicron variant.

Last updated on Sept 7 to include details on the Mu variant.

Skimm'd by Maria Martinolich and Kamini Ramdeen

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