The Centers for Disease Control and Prevention issued new masking guidelines on Tuesday, advising that people vaccinated against Covid-19 should start wearing masks again in public, indoor spaces in parts of the country where the virus—including the highly contagious Delta variant—is surging. That includes Florida, which on July 27 was averaging 12,496 daily cases, a 124 percent increase over the previous 14 days. Sarasota County is currently averaging 124 daily positive cases and Manatee County is averaging 142. On July 28, Sarasota Memorial Hospital was caring for 92 Covid-positive patients, with 21 of them in the ICU. The hospital's seven-day positivity rate is 10.5 percent.

In its update, the CDC also recommended masking for teachers, staff, students and visitors in schools, regardless of whether or not they've been vaccinated. Currently, 30 percent of children between 12 and 17 have received the vaccine. However, on Tuesday, July 13, the Sarasota County School Board unanimously voted to make masks optional for children during the 2021-2022 school year.

At a news briefing on Tuesday, CDC director Dr. Rochelle Walensky said the agency updated its guidelines based on new scientific data that shows that even those who are fully vaccinated can contract Covid-19 and carry the virus in high amounts. However, she emphasized, the vast majority of transmissions are still from unvaccinated people. "Vaccines continue to do an exceptional job preventing serious illness, hospitalization, and death," Walensky said. "I believe that masking right now, especially for the unvaccinated, is a temporary measure. What we really need to do to drive down transmission is to get people vaccinated and, in the meantime, to use masks."

Delta remains the predominant variant circulating in the U.S., Walensky noted, adding that, "In recent days, I've seen new scientific data from outbreak investigations showing that the Delta variant behaves uniquely differently from past strains of the Covid-19 virus."

Walensky acknowledged that the new guidance might be frustrating for many Americans. "Eighteen months into this pandemic, people are tired—there are mental health challenges, and a lot of continued sickness and death," she said. "I know, in the context of all that, it is not a welcome piece of news that masking is going to be a part of people's lives who have already been vaccinated.

"This was not a decision that was taken lightly," she continued. "Scientific and public health experts who saw this data universally said it required action. The largest concern that we in public health and science have is a variant that has the potential to evade our vaccines."