The White House
- The Delta variant is the "greatest threat" to US COVID-19 efforts, Dr. Anthony Fauci said Tuesday.
- He said its prevalence in the US doubled within 2 weeks, a worrying sign.
- The variant is more transmissible and dangerous than other types of the coronavirus.
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The proportion of Delta variant coronavirus cases in the US doubled in two weeks, Dr. Anthony Fauci said on Tuesday.
Speaking at a press briefing, Fauci, the White House chief medical advisor, said the variant was currently the "greatest threat" to the US efforts to eliminate COVID-19.
20.6% of the COVID-19 in the US are now due to the Delta variant. That is about double the rate seen on June 5, when the variant made up 9.9% of cases.
On May 22, 2.7% of cases were caused by the Delta variant, Fauci said.
He said the US seems to be "following the same pattern" as the UK, where the variant quickly became dominant and now makes up 99% of cases.
In an interview with "Good Morning America" on Friday, Centers for Disease Control and Prevention director Dr. Rochelle Walensky warned that the variant would likely become dominant in the US in the coming months.
On Monday, the World Health Organization called the Delta variant the "fittest" strain of the coronavirus yet.
That is because, compared to the Alpha variant, which to date still dominant in the US, the Delta variant is a lot more transmissible.
It also appears to cause more hospitalizations and seems more likely to break through the protection given by one dose of the Pfizer and AstraZeneca vaccines.
Two doses of those vaccine are still effective at preventing symptomatic disease.
It is not clear how much protection the Moderna and Johnson and Johnson vaccines give against the variant.
On Friday, President Joe Biden urged Americans to get fully vaccinated.
He warned that young adults are particularly vulnerable, as they are less likely to be vaccinated and more likely to be socializing than older people.