Fauci Says the Delta Variant Is the 'Greatest Threat' to Ending the COVID Pandemic in the U.S.

Susan Walsh/AP/Bloomberg via Getty Dr. Anthony Fauci

Cases of COVID-19 are slowing in the United States as more Americans get vaccinated, but getting to the end of the pandemic is going to take longer with the highly contagious Delta variant spreading throughout the country.

In the last week, cases from the Delta variant have doubled, up to 20.6%, and federal health experts expect it to become the dominant strain in the next few weeks.

"The Delta variant is currently the greatest threat in the U.S. to our attempt to eliminate COVID-19," Dr. Anthony Fauci, the nation's top infectious diseases expert, said during a White House briefing on Tuesday.

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The variant, which was first identified in India, has spread faster than other strains and led to more hospitalizations, though it does not appear to be more deadly. Testing also shows that the COVID-19 vaccines from Pfizer and Moderna are nearly fully effective against the Delta strain, preventing infection in around 94% of fully vaccinated people.

"The news that's so important is that the vaccines that we have now, that we've done so well in distributing … over 65% of the adult population has received at least one dose. We're doing well with a vaccine that does quite well against this problematic variant," Fauci told Savannah Guthrie on Today Wednesday morning.

Fauci emphasized, though, that "it's the unvaccinated people that we're concerned about."

"There are some states that are less than 50% [vaccinated]," he said. "We've got to get younger people, particularly aged 18 to 26. Many people just need more information. They've let it go, they haven't paid attention to it. They need to pay attention to it now, because if they are unvaccinated they're at risk."

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Fauci also urged people to get vaccinated to protect those who can't, such as kids under 12 years old.

"The best way to protect the children is to bring the level of virus circulation in the community down. The best way to do that is for those - i.e., adults - who are eligible for vaccination to get vaccinated, so you're not only protecting yourself, but by bringing the level of virus down in the community you're indirectly protecting the children who can't yet get vaccinated," he said.

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And kids unable to get vaccinated should continue to wear masks and follow safety precautions, Fauci added.

If more people get vaccinated, Fauci said, they can prevent COVID-19 from continuing to mutate and create more virulent strains like the Delta variant.

"Another important reason why we need to get vaccinated: viruses don't mutate if they don't replicate," he said. "If you give them the opportunity to replicate by allowing them to spread from person to person, you're giving them the perfect opportunity to mutate even more and perhaps evade the vaccine."

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As of June 23, more than half of the U.S. population, or 53.5% of Americans, have received at least one dose of a COVID-19 vaccine and 45.3% are fully vaccinated, according to the Centers for Disease Control. Of the vaccine-eligible Americans, meaning those aged 12 and up, 62.6% have received at least one dose and 53% are fully vaccinated.

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