The delta variant of COVID-19 spreads as easily as chickenpox and may cause more and more serious disease in the vaccinated than previously thought, according to an internal government document that says the “war has changed” and the Centers for Disease Control and Prevention must retool its public messaging on the coronavirus.
The document, obtained by The Washington Post, outlines data that say vaccinated persons could transmit the virus as easily as unvaccinated persons.
Those findings were the foundation for a reversal in CDC guidance this week, in which officials said vaccinated persons should once again wear masks indoors in some places. Critics said it was confusing for the public to see the recommendations before the data is published.
The CDC is expected to release more data on Friday as it grapples with how to promote the vaccines even as data suggest they aren’t a cure-all, as sometimes advertised. Unpublished data includes findings from a July 4 outbreak in Provincetown, Massachusetts, in which vaccinated and unvaccinated persons spread the virus at similar rates.
Persons infected with delta “shed more virus, about 1,000 times than if they would if they were with the standard parent strain,” Dr. William Schaffner, an infectious disease expert at Vanderbilt University, told The Washington Times. “There’s something about that spike protein that allows it to enter the cell very readily.”
“If you have much much more virus in the back of the throat, when you exhale you would exhale a much larger dose of virus, which adds to its contagiousness,” he said.
Internal CDC documents say local health departments are worried that people will no longer trust the vaccines as top officials detail so-called “breakthrough” infections and transmission even among those who are fully vaccinated, according to The Post.
Experts say the public will need to get used to a new reality in which virus is detected in people regardless of vaccination status, so the real question is whether the shots still provide protection against severe disease, hospitalization and death. State officials and doctors say vaccinated persons occasionally must be hospitalized but the overwhelming majority of patients are unvaccinated.
“It’s really about 98% are either unvaccinated completely or received one dose,” Dr. Schaffner said. “It’s unusual for a vaccinated person to require hospitalization.”
The most severe breakthrough infections appear to be striking the elderly and medically frail because they haven’t mounted a solid immune response.
Dr. Catherine O’Neal, a doctor at Louisiana State University, told CNN that about half of her patients are under age 50. They are “all unvaccinated,” she said.
Elderly patients, especially those over age 80, account for most of the breakthrough cases of the vaccinated who arrive in her ward.
“These are patients that we don’t expect to make great antibodies. We don’t expect them to respond to the vaccine,” Dr. O’Neal said.
Some places, including Israel, have begun administering booster doses of the Pfizer-BioNTech vaccine to older persons to combat the variant.
Pfizer also recently said a third dose generally provides more protection against the delta strain.
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