Chilling new research about the transmissibility and severity of the Delta variant drove the CDC’s about-face decision on Wednesday that urged mask use indoors for everyone, The Washington Post reports.
An internal CDC slide deck obtained by the Post warns:
- Vaccinated people infected with the Delta variant may transmit the virus as easily as unvaccinated people.
- Delta likely causes more severe disease than earlier strains.
- Delta is more transmissible than smallpox, the 1918 flu, Ebola, MERS, and SARS.
- “The war has changed.”
The research underlying the stark CDC assessment is expected to be released today, according to The New York Times.
The finding largely responsible for shifting CDC attitudes was that vaccinated people infected with Delta can have large amounts of the virus in the nose and throat.
Another possible motivator: Data on Provincetown, Massachusetts July 4th celebrations that led to nearly 900 COVID-19 cases—almost three-quarters of which were among fully vaccinated people.
A penultimate slide in the CDC urges the agency to emphasize in its communications that vaccines still reduce the likelihood of severe disease and death, NPR reports. However, an estimated 35,000 fully vaccinated American are infected with the coronavirus each week.