What Are the New COVID-19 Strains, and Do They Infect Kids More Easily?

In addition to all the news about the COVID-19 vaccine, you’ve probably been hearing a lot about new strains of COVID-19.

Researchers are still gathering information about these new variants.

Connecticut Children’s Physician-in-Chief Juan Salazar, MD, MPH, shares what we know so far.

What does it mean when there’s a new “strain” or “variant” of COVID-19?

A strain or variant is a slightly different version of a virus. Viruses grow inside a person’s body by making copies of themselves. Sometimes, these copies contain random differences, or mutations. Most of the time mutations don’t change anything significant. Sometimes they harm a virus. And sometimes they help it.

If a mutated version of a virus survives, it can start spreading in a community. For example, every flu season, there are usually several strains of the flu going around.

That’s what we’re hearing about now with the new strains of COVID-19.

> Related: Why Your Child Needs Their Flu Shot ASAP


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Which COVID-19 variants are in the United States?

There are lots of COVID-19 strains in existence around the globe, but experts are most concerned about the handful below. They’re named based on where they originated – for example, the U.K. variant was first detected in the United Kingdom.

  • K. or British variant, also known as B117
  • South Africa variant, aka 501Y.V2 or B.1.351
  • Brazil variant, aka P.1
  • California variant, aka CAL.20C

All of these strains have been detected in the United States, and the U.K. and South African variants have been confirmed in Connecticut. According to the Centers for Disease Control and Prevention, the U.K. variant might become the dominant strain in the U.S. by March.

How are the new variants of COVID-19 different from previous strains?

The new strains all appear to spread more easily than previous strains of COVID-19 – for example, some data show that the U.K. strain spreads up to 70% more easily, and that the South African strain spreads up to 50% more easily.

> Related: What Should I Do When My Child Has a Common Cold During COVID-19?

Are the new strains of COVID-19 more dangerous?

Some information suggests that the U.K. variant may cause worse disease than previous strains, but researchers need more data to confirm this.

So far, the Brazil, California and South Africa variants do not appear to cause more serious illness or increased risk of death than previous strains of COVID-19.

Are children more likely to get sick from the new strains of COVID-19?

In the first wave of COVID-19, for reasons that we still don’t know, COVID-19 was more likely to infect adults than children. But in the past two to three months in the U.S., there has been a significant increase in the percentage of children diagnosed with COVID-19.

At this point, it doesn’t seem that the new strains have anything to do with this – but eventually, they could. We’re keeping a close eye on it.

Again, for the most part, the new strains do not appear to lead to more serious illness for the individuals they infect, including young people and children.

Will the COVID-19 vaccine still work against the new strains? Why?

Pfizer and Moderna have both said their COVID-19 vaccines will work against the U.K. variant. This is likely because the part of the virus that mutated isn’t involved in how the vaccines work.

There are concerns that the currently authorized vaccines, and other vaccines that are close to authorization, could prove less effective against some of the other new variants. For example, some studies suggest that Pfizer and Moderna vaccines are about half as effective against the South African variant.

But there are two pieces of good news:

First, the existing vaccines still offer some protection against all of the variants. The protection is just reduced a bit.

Second, the science behind these mRNA vaccines makes them relatively easy to adjust – so even as Moderna and Pfizer are producing more vaccines to roll out across the country, they are figuring out how to tweak the mRNA for future doses to better protect against new variants.

> Related: Now That There’s a COVID-19 Vaccine, When Will Life Go Back to “Normal”?

Should my family be worried about the new strains of COVID-19?

We need to be more careful than ever, since the U.K. and South African strains are already in Connecticut, and the Brazil and California variants have been confirmed elsewhere in the U.S. And we know that all of these strains spread very easily.

Now more than ever, it’s important to wear masks, social distance and avoid risky activities. Get tested and self-quarantine if you might be sick. As always, practice great hand hygiene.

And once the COVID-19 vaccine becomes available to your family, it will be important to get both doses.

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