Delta variant now the dominant COVID strain in NYC as cases rise nationwide

The Delta variant of COVID-19 has become the dominant strain of the virus in New York City, as cases rise locally and across the nation.

The head of the CDC says that it is clear, unvaccinated people are driving the surge and are the most at-risk.

According to Mayor Bill de Blasio, the Delta variant makes up more than two-thirds of the new cases in New York City, but de Blasio says he does not expect to take any drastic measures yet.

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"We're not seeing any real movement in hospitalizations and that's really important," de Blasio said. "0.31 hospitalizations per 100,00 people, it's a very low rate and it has stayed low in recent weeks."

In California, a mask mandate is returning to Los Angeles County beginning tomorrow at 11:59 p.m., meaning people will have to wear a mask in any public indoor setting. This comes just one month after California's reopening.

RELATED: COVID-19 becoming ‘pandemic of the unvaccinated’, CDC director says

During a White House press briefing, Dr. Rochelle Walensky said cases in the U.S. were up about 70% over the last week, hospital admissions were up 36% and deaths rose by 26%.

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"There’s a clear message that is coming through: this is becoming a pandemic of the unvaccinated," Walensky said. "We are seeing outbreaks of cases in parts of the country that have low vaccination coverage because unvaccinated people are at risk. And communities that are fully vaccinated are generally faring well."

Nearly all hospital admissions and deaths, she said, are among the unvaccinated.