The Centers for Disease Control and Prevention had a warning for Americans about the dangers of the Delta variant of COVID-19, saying it is one of the most infectious respiratory diseases ever seen by scientists to date.

The dire comments came from CDC Director Dr. Rochelle Walensky during a White House coronavirus briefing on Thursday, where she said, “The delta variant is more aggressive and much more transmissible than previously circulating strains. It is one of the most infectious respiratory viruses we know of, and that I have seen in my 20-year career.”

The Delta variant is a highly contagious strain of COVID-19 that is infecting people and causing virus cases to surge across the country. The Delta variant, which was first identified in India, has been detected in all 50 states of the U.S. and now accounts for 83% of new cases of COVID, according to the CDC.

The variant is more transmissible because people infected with the Delta variant can carry up to 1,000 times more of the virus in their nasal passages than the original strain of the virus, new data has suggested, as reported by CNBC.

The seven-day average of new positive cases of the virus in the U.S. is up about 53% from last week at 37,674 new cases per day, with hospitalizations at 3,500 per day, up 32% from last week, according to CNBC. COVID-19 deaths have also risen to about 240 per day during the same timeframe, up 19%, the news outlet said.

States with low vaccination rates are suffering from major spikes in Delta variant cases, with Florida, Texas and Missouri accounting for 40% of all new COVID cases nationwide, according to Jeff Zients, head of the White House COVID taskforce. Florida alone represents 1 in 5 of all new COVID-19 cases in the U.S. for the second continuous week, Zients said on Thursday.

Walensky also cited the Delta variant’s relentlessness, saying, “This virus has no incentive to let up, and it remains in search of the next vulnerable person to infect.”

However, the CDC has not changed its guidance on face masks for vaccinated people. In May, the agency said that vaccinated Americans did not need to wear face masks indoors or outdoors in most situations.

But the Delta variant is honing in on the unvaccinated. Over 95% of people admitted to hospital with COVID symptoms are unvaccinated, The Independent reported. And as many as 99.5% of all COVID-19 deaths are also unvaccinated people, CNBC said.

As of Friday, over 162.1 million people have been fully vaccinated against COVID-19, accounting for 48.8% of the U.S. population, according to data from the CDC.

Pfizer, Moderna and Johnson & Johnson said they would supply around 3.5 billion vaccine doses at cost or discount to poor nations Pfizer, Moderna and Johnson & Johnson said they would supply around 3.5 billion vaccine doses at cost or discount to poor nations Photo: AFP / PIERRE-PHILIPPE MARCOU