The unvaccinated "are 10 times more likely to be hospitalized and 11 times more likely to die," CDC director Rochelle Walensky said at Friday's White House COVID briefing.

Three new studies from the CDC show vaccines still dramatically reduce the risk of hospitalization and death amid the delta surge. 

A study of U.S. veterans fully vaccinated with Pfizer and Moderna found no real change in vaccine effectiveness against hospitalization pre-delta to post-delta. A second study of all three vaccines across nine states found vaccine effectiveness against hospitalization was 86% for all age groups. A third study of all three vaccines across 13 jurisdictions found vaccines performed roughly equally well protecting against hospitalization and death during the delta surge compared to pre-delta.

Across the studies, vaccines remained 86-87% effective against preventing hospitalizations.

But effectiveness dropped more for people ages 65 and older in recent months compared to before delta, likely due a combination of vaccine effectiveness fading over time and the slight impact of the delta variant on vaccine efficacy.

Vaccines are losing some of their effectiveness when it comes to preventing mild infections among the vaccinated.

-ABC News' Sony Salzman

While awaiting Pfizer trial data for kids ages 5 to 11, the Food and Drug Administration is vowing not to cut corners.

The FDA said, "it’s critical that thorough and robust clinical trials of adequate size are completed to evaluate the safety and the immune response."

"Children are not small adults -- and issues that may be addressed in pediatric vaccine trials can include whether there is a need for different doses or different strength formulations of vaccines already used for adults," the FDA said.

When the FDA receives a completed emergency use authorization request, "the agency will carefully, thoroughly and independently examine the data to evaluate benefits and risks and be prepared to complete its review as quickly as possible, likely in a matter of weeks rather than months."

"However, the agency’s ability to review these submissions rapidly will depend in part on the quality and timeliness of the submissions by manufacturers," the FDA added.

-ABC News' Anne Flaherty

All employees of Milwaukee Public Schools must provide proof of COVID-19 vaccination by Nov. 1, unless they qualify for a medical or religious exemption, school board members voted unanimously on Thursday night.

The board also decided that staff who qualify for an exemption must take COVID-19 tests twice weekly. Anyone who does not comply with the new vaccine mandate or is not exempt would be placed on unpaid leave and ultimately could lose their job.

Students are not required to get vaccinated, but the board approved monetary incentives of $100 for those who are 12 and older and can provide proof of vaccination by the Nov. 1 deadline.

The Los Angeles Unified School District's Board of Education unanimously voted Thursday to require the COVID-19 vaccine for all eligible students.

All students ages 12 and up will be required to be fully vaccinated by Jan. 10, 2022, unless they have a "medical or other exemption," said the district, which is the second-largest in the nation with over 600,000 students.

All teachers and staff are already required to be vaccinated by Oct. 15.

"Today's decision furthers our longstanding commitment to ensure the safety of our students, families, and staff," Board President Kelly Gonez said in a statement. "The vaccine is the single best way to protect students and schools from COVID-19."

The Texas attorney general has filed lawsuits against six school districts that mandate masks, the office said Friday.

The lawsuits target the school districts of Richardson, Round Rock, Galveston, Elgin, Spring and Sherman for flouting Gov. Greg Abbott’s executive order prohibiting local entities from requiring masks -- what Texas Attorney General Ken Paxon referred to in a statement as "acts of political defiance."

In a statement to ABC News, Sylvia Wood, a spokesperson for Spring Independent School District, said the district had yet to be served and had no details about the lawsuit beyond a press release.

"Spring ISD will let the legal process unfold and allow the courts to decide the merits of the case," Wood said.

Elgin Independent School District Superintendent Jodi Duron also told ABC News the school district had not been served yet, and that schools in Travis County, part of Elgin ISD, are required to have students wear masks. "To the District’s knowledge, the Travis County Order has not been suspended," she said.

Round Rock Independent School District spokesperson Jenny LaCoste-Caputo told ABC News the school district is following Texas Education Agency guidance that allows for mask requirements "for adults or students for whom it is developmentally appropriate" and is working with local authorities "who advise us that masks remain an essential tool in stemming the spread of COVID-19 in our classrooms."

Sherman Independent School District told ABC News in a statement that it had not received any information on the lawsuit yet and for now "will continue to focus on promoting a safe and healthy learning environment for our students and staff."

ABC News has reached out to the other school districts for comment.

Nearly 90 school districts currently have mask mandates, according to a list compiled by Paxton's office. The attorney general anticipates more lawsuits if school districts "continue to defy state law," his office said in a statement.

Several school districts have sued the state to challenge the ban on mask mandates.

Last week, the Texas Education Agency said it is not enforcing the governor's executive order "as the result of ongoing litigation."