The Delta variant is much more contagious. More likely to break through protections afforded by the vaccines and may cause more severe disease than all other known versions of the virus, according to an internal presentation circulated within the Centers for Disease Control and Prevention.
Dr. Rochelle P. Walensky, the director of the agency, acknowledged on Tuesday that vaccinated people with so-called breakthrough infections of the Delta variant carry just as much virus in the nose and throat as unvaccinated people and may spread it just as readily, if less often.
But the internal document lays out a broader and even grimmer view of the variant.
The Delta variant is more transmissible than the viruses that cause MERS, SARS, Ebola, the common cold, the seasonal flu, and smallpox. It is as contagious as chickenpox, according to the document, a copy of which was obtained by The New York Times.
The immediate next step for the agency is to “acknowledge the war has changed,” the document said. Its contents were first reported by The Washington Post on Thursday evening.
The document’s tone reflects alarm among C.D.C. scientists about Delta’s spread across the country, said a federal official who has seen the research described in the document. The agency is expected to publish additional data on the variant on Friday.
“The C.D.C. is very concerned with the data coming in that Delta is a very serious threat that requires action now,” the official said.
Make wearing a mask a normal part of being around other people. The appropriate use, storage, and cleaning, or disposal of masks are essential to make them as effective as possible.
Here are the basics of how to wear a mask:
- Clean your hands before you put your mask on, as well as before and after you take it off, and after you touch it at any time.
- Make sure it covers both your nose, mouth and chin.
- When you take off a mask, store it in a clean plastic bag, and every day either wash it if it’s a fabric mask, or dispose of a medical mask in a trash bin.
- Don’t use masks with valves.