(CNN) As experts race to mitigate the spread of Covid-19 by encouraging vaccinations and mask wearing, hospital systems in a handful of states are now straining to keep up with the surge.
Eight states, many of which have lagged the national average for vaccinations, have Covid-19 patients that account for at least 15% of their overall hospitalizations: Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, Nevada and Texas, according to a CNN analysis of data from the US Department of Health and Human Services.
Of all Covid-19 hospitalizations, these eight states' combined totals make up approximately 51% of patients, though the states account for only around 24% of the nation's population, according to Census data.
"In the past week, Florida has had more Covid cases than all 30 states with the lowest case rates combined. And Florida and Texas alone have accounted for nearly 40% of new hospitalizations across the country," White House Covid-19 response coordinator Jeff Zients said Thursday during a White House briefing.
Data published Friday by the Florida health department reported 151,415 new Covid-19 cases over the past week, a record for a seven-day period during the pandemic.
Florida has the second-highest rate of new cases per capita, with slightly more than 100 new cases per 100,000 people each day over the past week. That's behind only Louisiana.
On the heels of that, Florida is the latest state to report 50% of its residents as fully vaccinated, according to CDC data published Thursday.
The percentages of Covid-19 patients in intensive care units are even worse, with Florida, Louisiana and Mississippi approaching half of ICU beds in use for such patients, HHS data from Thursday show.
Mississippi on Friday reported 5,023 new cases, another daily record, the state Department of Health said. Of the new cases, 98% of those are in unvaccinated people, the state's dashboard shows.
Gov. Tate Reeves said a shortage of health care workers is exacerbating the strain on hospitals, saying the state lost 2,000 health care workers last year.
He said a call has gone out to out-of-state workers -- 73 hospitals have requested 65 physicians, 920 nurses, 41 CRNAs, 59 advanced practice nurses, 34 physician assistants, 239 respiratory technicians and 20 EMT paramedics.
In Florida, Brevard County officials issued an urgent plea this week for residents to try to avoid using ambulance services for nonemergency calls or going to hospitals for Covid-19 tests.
First responders and departments are feeling the effects of the Delta coronavirus variant surge throughout the country.
In Memphis, Tennessee, emergency departments are overworked due to the pandemic, with August having the potential to be the busiest month in the history of the city's fire department, Fire Chief Gina Sweat said.
Due to constraints "on all levels" of bed capacity, Vanderbilt University Medical Center in Nashville is limiting elective cases and declining transfer requests from many other facilities, officials said while announcing the hospital and emergency department are "completely full."
And Chief Medical Officer Dr. Geoff Lifferth at Sumner Regional Medical Center in Gallatin, Tennessee, said the hospital had no more open beds. "As an ER doc and a healthcare administrator, this past week has been one of the most exhausting and disheartening of my career," he said in an emotional Facebook post.
In Texas, the Department of State Health Services said a shortage of pediatric ICU beds in Dallas County is related to a shortage in medical personnel.
"Hospitals are licensed for a specific number of beds and most hospitals regularly staff fewer beds than they are licensed for. They can't use beds that aren't staffed. With the increase in COVID cases, hospitals are experiencing a shortage of people to staff the beds that they are licensed for," health department spokesperson Lara Anton said.
Gov. Greg Abbott announced Wednesday that more than 2,500 medical personnel will be deployed to hospitals around the state to care for the increasing number of Covid-19 patients.
In Oregon, Gov. Kate Brown said Friday she is ordering the deployment of up to 1,500 Oregon National Guard members to support health care workers due to a surge of hospitalizations in the state due to the rapid spread of the Delta variant.
"I know this is not the summer many of us envisioned, with over 2.5 million Oregonians vaccinated against COVID-19," Brown said. "The harsh, and frustrating reality is that the Delta variant has changed everything. Delta is highly contagious, and we must take action now.
The FDA on Thursday authorized an additional third dose to be administered to people with compromised immune systems. On Friday, vaccine advisers to the CDC voted unanimously on Friday to recommend an extra dose of vaccine for some immunocompromised people. CDC Dr. Rochelle Walensky quickly endorsed the vote, which means people can begin getting third doses right away.
At a meeting of CDC vaccine advisers, Dr. Heather Scobie said a disproportionate number of vaccine breakthroughs are among immunocompromised people. Almost one-third -- 32% -- of vaccinated breakthrough cases are among that group, she said.
While immune compromised people make up about 2.7% of the adult population -- about 7 million people -- they're more vulnerable to infection, said Dr. Amanda Cohn, the executive secretary of the CDC's Advisory Committee on Immunization Practices.
She said vaccine effectiveness is about 59% to 72% in immunocompromised people, compared to 90% to 94% overall.
"Immunocompromised people are more likely to get severely ill from Covid-19. They are at higher risk for prolonged SARS-CoV-2 infection and shedding and viral evolution during the infection and treatment, particularly amongst hospitalized patients," Cohn said.
With the school year getting underway, the debate over mask mandates among parents, educators and political leadership continues nationwide, as children under age 12 are not yet eligible for Covid-19 vaccines.
Over the past few days, heated scenes have played out in Georgia and Tennessee as local school boards and officials considered mask mandates for staff and students, only to be met with loud opposition from some parents.
In suburban Atlanta, more than 550 cases have been reported this week in the Cobb County School District. Cobb County does not mandate masks but does "strongly encourage" them for students and staff, according to the district's public health guidelines posted on its website.
In Florida, three educators in Broward County died from Covid-19-related complications this week, the teachers union president, Anna Fusco, told CNN. The educators died in a roughly 24-hour span between Monday night and Wednesday morning, she said.
Broward County School Board Chair Rosalind Osgood responded Friday on CNN to a question about reports that three of the educators were unvaccinated.
"I was also told they were unvaccinated," she said.
The district, which opens classrooms to students next week, is using money to encourage staff members to get vaccinated.
Broward County has had 138 employees test positive for Covid-19 since August 1, according to the system's Covid dashboard, which was updated on Thursday.
The Ware County School System in South Georgia will close until August 27, due to a sharp increase in the number of Covid-19 cases reported among students and staff members, the district announced Friday.
Ware County Schools, which has 5,900 students, on Friday reported 76 cases Covid-19 among students and 67 positive tests among staff. Almost 680 students and 150 employees are quarantined.
"Some staff members are dealing with their own illness or sickness in their families, so they are unable to work right now. Staff members at two schools are grieving significant losses," the district said on Facebook. "For those reasons and others, we felt the best course of action was to hit the pause button and give staff and students time to recover physically and emotionally."
In-season extracurricular practices and competitions will continue as scheduled, the release said.