New Delhi: 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 (CDC) and Prevention.
The Director of the agency, Dr Rochelle Walensky, acknowledged on Tuesday that vaccinated people with so-called breakthrough infections of the Delta variant carry just as much virus in their nose and throat as unvaccinated people and may spread it just as readily, if less often, News18 reported quoting New York Times.
The internal document lays out a broader and 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, and it is as contagious as chickenpox, according to the document, a copy of which was obtained by The New York Times.
The war has changed
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. It is expected to publish additional data on the variant Friday.
“The CDC is very concerned with the data coming in that delta is a very serious threat that requires action now,” the official said.
Vaccinated people are spreading the virus
The new data suggest that vaccinated people are spreading the virus and contributing to those numbers although probably to a far lesser degree than the unvaccinated.
Walensky has called transmission by vaccinated people a rare event.
Masking guidelines
The agency’s new masking guidelines for vaccinated people, introduced Tuesday, were based on the information presented in the document. The CDC recommended that vaccinated people wear masks indoors in public settings in communities with high transmission of the virus.
But the internal document hints that even that recommendation may not go far enough. “Given higher transmissibility and current vaccine coverage, universal masking is essential,” the document said.
The agency’s data suggest that people with weak immune systems should wear masks even in places that do not have high transmission of the virus.
Ten times higher infection
Infection with the Delta variant produces virus amounts in the airways that are tenfold higher than what is seen in people infected with the Alpha variant, which is also highly contagious, the document noted.
Detailed analysis of the spread of cases showed that people infected with Delta carry enormous amounts of virus in their nose and throat, regardless of vaccination status, according to the CDC document.
Infection with the Delta variant may be more likely to lead to severe illness, the document noted. Studies from Canada and Scotland found that people infected with the variant are more likely to be hospitalized, while research in Singapore indicated that they are more likely to require oxygen.
Still, the CDC’s figures show that the vaccines are highly effective in preventing serious illness, hospitalization and death in vaccinated people, the report quoted experts as saying.
“Overall, delta is the troubling variant we already knew it was,” said John Moore, a virologist at Weill Cornell Medicine in New York. “But the sky isn’t falling and vaccination still protects strongly against the worse outcomes.”
