CDC internal reports call delta variants as infectious as chickenpox

According to an internal presentation circulated within the Centers for Disease Control and Prevention, the delta mutant is much more contagious, more likely to break through the protection provided by the vaccine, and more than all other known versions of the virus. It can cause serious illness.

The agency’s director, Dr. Rochelle P. Warrensky, Approved on Tuesday People vaccinated against the so-called breakthrough infection of the delta variant carry as much virus into the nose and throat as unvaccinated people, and can spread as easily, if less frequently. there is.

However, the internal document lays out a wider, more glittering view of the variant.

More delta variants More contagious than the viruses that cause MERS, SARS, Ebola, colds, seasonal flu, and smallpox, and as contagious as chickenpox, a copy was obtained by the New York Times.

The agency’s next step is to “acknowledge that the war has changed,” the document said.The content is First reported By The Washington Post on Thursday night.

The tone of the document reflects caution among CDC scientists about the spread of the Delta across the country, federal officials said after seeing the study described in the document. The agency will publish additional data on the variant on Friday.

“The CDC is very concerned about the data that Delta is a very serious threat and needs to take action now,” officials said.

As of Thursday, there were an average of 71,000 new cases per day in the United States. New data suggest that vaccinated people spread the virus and contribute to their number — perhaps far less than unvaccinated people.

Dr. Warensky called infections by vaccinated people a rare event, but other scientists suggested that it might be more common than once thought.

The authorities’ new masking guidelines for vaccinated people, introduced on Tuesday, were based on the information presented in the document. The CDC recommended that vaccinated people wear masks indoors in public places in areas where the virus is prevalent.

However, internal documentation suggests that even that recommendation may not be sufficiently advanced. “Universal masking is essential given its higher contagiousness and current vaccine coverage,” the document states.

Official data suggest that people with a weak immune system should wear masks even in areas where the virus infection rate is not high. Therefore, Americans who are in contact with infants, the elderly, or other vulnerable people need to be vaccinated.

According to data collected by the CDC as of July 24, quoted in an internal presentation, there are approximately 35,000 symptomatic infections per week among 162 million vaccinated Americans. However, the actual incidence can be high because authorities are not tracking all mild or asymptomatic infections.

Infection with the delta mutant causes viral load in the respiratory tract. This is ten times the amount found in people infected with the alpha mutant, and the document states that it is also highly contagious.

The amount of virus in people infected with Delta Thousand times or more According to a recent study, it is more than found in people infected with the original version of the virus.

The CDC document relies on data from multiple studies, including an analysis of recent outbreaks in Provincetown, Massachusetts. This started after the July 4th festival in town. By Thursday, the cluster had grown to 882 cases. About 74 percent were vaccinated, according to local health officials.

A detailed analysis of the spread of the cases, according to the CDC document, found that people infected with Delta had large amounts of the virus in their noses and throats, regardless of vaccination status.

“This is one of the most striking examples of citizen science I’ve seen,” said Dr. Celine Gounder, an infectious disease specialist at the Bellevue Hospital Center in New York. “People involved in the outbreak of Provincetown paid close attention to making a list of their contacts and exposures.”

Infection with the delta mutant is likely to lead to serious illness, the document states. Studies in Canada and Scotland found that people infected with the mutant were more likely to be hospitalized, but studies in Singapore showed that they were more likely to require oxygen.

Still, the CDC figures show that the vaccine is very effective in preventing serious illness, hospitalization and death in vaccinated people, experts said.

John Moore, a virologist at Weil Cornell Medicine in New York, said: “But the sky hasn’t fallen and vaccination still provides strong protection from bad consequences.”