New evidence showing the delta variant is as contagious as chickenpox prompted U.S. health officials to consider changing advice on how the nation fights the coronavirus.
Recommending masks for everyone and requiring vaccines for doctors and other health care providers are among measures the Centers for Disease Control and Prevention is considering, according to internal documents obtained by the Washington Post.
The presentation for CDC staff tells them to “acknowledge the war has changed.” It also notes that infections in vaccinated people may be as transmissible as in the unvaccinated.
The documents appear to be talking points for CDC staff to use in explaining the dangers of the delta variant and “breakthrough″ infections that can occur after vaccination.
The report, to be released by the CDC, comes from a recent investigation of a coronavirus outbreak in Cape, Cod, Massachusetts.
In that July 4 outbreak, vaccinated and unvaccinated people had nearly the same amount of virus recovered from test samples, indicating that vaccinated people are just as contagious as unvaccinated people when it comes to the delta variant.
With previous strains, vaccinated people who became infected with the coronavirus had much lower levels of virus, meaning they were less contagious. That may have now changed.
Earlier this week, the CDC changed its masking guidelines, recommending that even vaccinated people return to wearing masks indoors in parts of the U.S. where the delta variant of the coronavirus is fueling surges in new cases.
Citing new – but unreleased -- information about the variant’s ability to spread among vaccinated people, the CDC also recommended indoor masks for all teachers, staff, students and visitors at schools nationwide, regardless of vaccination status.
One chart in the slide presentation shows that the delta variant could be as contagious as chickenpox, one of the more transmissible viruses. It spreads more easily than the common cold, the 1918 flu and smallpox.
It also says that in addition to being more contagious, the delta variant likely increases the risk of severe disease and hospitalization, compared with the original strain.
The presentation also recommends that the agency ramp up communications so the public will understand that vaccines still greatly reduce the risk of death and severe disease.
While most new infections are still occurring among unvaccinated people, the CDC estimates that 35,000 fully vaccinated Americans – out of more than 162 million — may get infected with the coronavirus every week.
NPR's Joe Neel, Rob Stein and Jane Greenhaigh contributed to this report.
