New evidence suggests that vaccinated people may transmit the variable Delta

COVID-19 remains an enigma. The U.S. Centers for Disease Control and Prevention (CDC) again recommended indoor masks two days ago for people vaccinated against COVID-19 more than two months after announcing otherwise. According to the latest guide from the health authority, Fully vaccinated people are advised to wear face masks in “Closed public environments” in places with “significant” or “high” transmission levels, as well as their use in schools for the next school year.

Last May, the CDC had withdrawn the jugular directive for people vaccinated in the United States, corn cities like Los Angeles and Philadelphia have reinstated the mandate. Community transmission and personal risk levels are two factors to consider, experts say.

COVID vaccines have been shown to be effective against the more severe versions of the disease that lead to hospitalization and death. But the experts say it is not the same for everyone and people need to consider factors such as community transmission, personal risk levels and their own risk tolerance when deciding what is in their best interest.

The new board of “Masking” The CDC relied in part on data showing that the virus can thrive in the respiratory tract of people who have been vaccinated. Now, new findings are expected for tomorrow Friday.

According to Dr Rochelle Walensky, director of the Centers for Disease Control and Prevention, the recommendation that people vaccinated in parts of the country dust off their masks was largely based on a disturbing finding. “New research has shown that vaccinated people infected with the Delta variant carry huge amounts of the virus in their nose and throat, ”he said. Walensky at the New York Times.

Discovery this contradicts what scientists had observed in vaccinated people infected with earlier versions of the virus, most of whom seemed unable to infect others. This conclusion was a blow to Americans: People with so-called “breakthrough” infections (which occur after a full vaccination) of the Delta variant can be just as contagious as people who have not been vaccinated, even if they have no symptoms.

It means that Fully immunized people with young children, elderly parents, or friends and family with weakened immune systems will need to be vigilant, especially in high transmission communities. Vaccinated Americans may need to wear masks to protect not only themselves, but also anyone in their orbit.

This new measure comes amid concerns about the dangerousness of the Delta variant and at a time when in the United States there is 67,000 cases nine per day on average. If vaccinated people transmit the Delta variant, they may contribute to the increases, although probably to a lesser extent than unvaccinated people.

The CDC has yet to release its data, frustrating experts who want to understand the basis for the change in opinion on masks. Four scientists familiar with the research said it was compelling and justified the CDC’s opinion that vaccinators once again wear masks in indoor public spaces.

The investigation was conducted by people outside the CDC., the scientists said, and the agency is working quickly to analyze and publish the results. The agency plans to release the investigation on Friday, an official said.

Some of the investigations may be related in part to an outbreak in Provincetown, Massachusetts, where the July 4 festivities caused 882 cases on Thursday. Almost three quarters of these people were fully vaccinated. The agency also tracked data from the Covid-19 Sports and Society Workgroup, a coalition of professional sports leagues that is testing more than 10,000 people at least daily and sequence all infections.

“It is not yet clear how common progressive infections are and how long the virus persists in the body in these cases. Progress is rare and unvaccinated people are at the origin of most of the transmission of the virus “said Dr Walensky. Critics suggest that even fully immunized people can be reluctant vectors for the virus. “We think they could do this on an individual level, so we’ve updated our recommendation,” Walensky added.

The new data does not mean that the vaccines are ineffective. Vaccines still powerfully prevent serious illness and death, as they were meant to do, and people with chronic infections rarely end up in hospital.

About 97% of people hospitalized with Covid-19 are not vaccinatedBut scientists even warned last year that vaccines might not completely prevent infection or transmission, according to CDC data. Earlier versions of the virus rarely crossed the vaccination barrier, prompting the CDC to warn in May that those vaccinated can go indoors without a mask.

The usual rules don’t seem to apply to the Delta variant

The variant Delta is twice as contagious as the original virus, and one study suggested that the amount of virus in unvaccinated people infected with Delta may be 1,000 times greater than that seen in people infected with the original version of the virus. Anecdotes of clusters of breakthrough infections have become increasingly common, with clusters of people vaccinated reporting colds, headaches, sore throats, or loss of taste or smell, symptoms of an infection. upper respiratory tract.

But the vast majority do not need intensive medical care, because the immune system produced by the vaccine destroys the virus before it reaches the lungs. “We will continue to see a huge, huge, huge impact on the severity of illness and hospitalization,” said Michal Tal, immunologist at Stanford University. “That’s really what the vaccine was made for.”

Vaccines against the coronavirus are injected into the muscle and most of the antibodies produced in response remain in the blood. Some antibodies can reach the nose, the main gateway for the virus, but not enough to block it. “Vaccines are beautiful, they work, they are amazing,” said Frances Lund, viral immunologist at the University of Alabama at Birmingham. “But they’re not going to give you that local immunity.”

When people are exposed to a respiratory pathogen, it can implant itself in the nasal mucosa, causing no damage beyond that. “If you walk down the street and take samples from people, you will find people who have viruses in their lining that are asymptomatic “said Dr Michael Marks, epidemiologist at the London School of Hygiene and Tropical Medicine. “Our immune system primarily fights these things most of the time.”

Corn the Delta variant seems to bloom on the nose, and its abundance may explain why more people than scientists predict are suffering from cold-like infections and symptoms.

Yet when the virus tries to enter the lungs, the immune cells of vaccinated people swell and quickly clear the infection before it can do much damage. This means vaccinated people must be infected and contagious for a much shorter period of time than unvaccinated people, Dr Lund said.

“But that doesn’t mean that the first few days, when they get infected, they can’t pass it on to another person.”added.

KEEP READING: