Citing Nature of Delta Variant, CDC Tells the Vaccinated to Resume Masking in Hot Spots

Amid a surge of COVID-19 cases nationwide, the CDC Tuesday recommended that vaccinated individuals revert to indoor mask wearing in hot-spot areas, due to the behavior of the more transmissible and contagious delta variant.

In rare cases of breakthrough infections with the delta variant, those who are vaccinated have the potential to transmit it to others, said CDC Director Rochelle P. Walensky, MD, MPH, but she stressed that COVID-19 is still largely being spread by the unvaccinated.

The news comes a day after major medical and health associations called for mandatory vaccinations for health care staff as the more transmissible delta variant spreads, especially in counties and states with lower vaccination rates.

During the spring, cases of COVID-19 and hospitalizations dropped as vaccine eligibility widened, but with the spread of the delta variant, the country is averaging more than 57,000 cases a day and 24,000 COVID-19 hospitalizations.

The amount of virus in vaccinated people with breakthrough infections is similar to levels in the unvaccinated, Walensky said during a media call. The CDC is following clusters where this is happening, she said, and some clusters are large; the amount of viral load is what gives the CDC reason to believe that transmission in vaccinated individuals is possible.

In addition, she noted that public health experts and scientists remain worried about the virus continuing to mutate and gain the ability to evade current vaccines.

Areas where indoor masking is recommended are those locales with “substantial or high” transmission of the virus. Substantial transmission is defined as 50 to 100 cases per 100,000 people over 7 days; high transmission, more than 100 cases per 100,000 people over 7 days.

Asked about whether or not the CDC would recommend a mask mandate for the federal workforce or the military, Walensky responded, “That is not something the CDC has jurisdiction over.”

Communities should consider what would most motivate the unvaccinated to get vaccinated, she said. If a business thinks that a mandate would help increase vaccine uptake, “then we would encourage businesses to do that.”

Walensky stressed that this is not a decision that was made lightly.

“This new data weighs heavily on me. This new guidance weighs heavily on me,” she said.