(CNN)A vast majority of US residents live in an area with high Covid-19 transmission, but hospitalization and death rates are significantly higher in states with the lowest vaccination rates.
In the 10 states with the lowest vaccination rates, fewer than 41% of their residents have been fully vaccinated. In the 10 states with the highest vaccination rates, more than 58% of their residents have been inoculated against coronavirus.
Hospitalization rates in those bottom 10 states are nearly four times higher, and death rates are more than 5.5 times higher than in the top 10 states, according to a CNN analysis of federal data.
Nearly 93% of the US population lives in an area with high Covid-19 transmission, according to the Centers for Disease Control and Prevention.
"We continue to see a rise in cases driven by the more transmissible Delta variant with cases concentrated in communities with lower vaccination rates," Jeff Zients, White House coronavirus response coordinator, said Wednesday at a virtual Covid-19 briefing. "So this remains a pandemic of the unvaccinated."
The 10 states with the lowest vaccination rates are Alabama, Mississippi, Wyoming, Idaho, Louisiana, Arkansas, West Virginia, Georgia, Tennessee and North Dakota. Data from the US Department of Health and Human Services shows an average of 39 people hospitalized with Covid-19 for every 100,000 residents in those states, compared to 10 for every 100,000 in the top 10 vaccinated states.
The top states with high vaccination rates are Vermont, Massachusetts, Maine, Connecticut, Rhode Island, Maryland, New Jersey, New Hampshire, Washington and New York.
In the 10 states with the lowest vaccination rates, there is an average of about 34 deaths per 1 million residents, and in states with the highest, the average is six deaths per 1 million, according to data from Johns Hopkins University.
CDC Director Dr. Rochelle Wallensky said at the news conference that the country is averaging about 500 Covid-19 deaths a day -- deaths that "remain largely preventable."
"In areas with low vaccination coverage, we continue to hear far too many heartbreaking stories of people who did not get vaccinated, only then to get severe Covid-19," she said. "In these areas, the data are showing us that the more people who are in the hospital, and tragically, more people are dying of Covid-19."
Child Covid-19 cases are steadily increasing as schools reopen
As Covid-19 cases and hospitalizations surge in the US, a health expert is warning that an accompanying rise in cases among children, many of whom aren't yet eligible to be vaccinated, will only worsen as schools resume classes.
That warning comes as top US health officials announced their intention -- subject to pending regulatory decisions -- to soon start allowing booster shots for any adult who'd received two mRNA Covid-19 vaccine shots.
As for youths: More than 121,000 child Covid-19 cases were reported in the US last week -- more than 14 times the weekly number in late June, when the figure was at the low point for 2021, the American Academy of Pediatrics reported this week.
This likely is just the start of what is to come, said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine.
"This is happening before school starts. Schools are opening now," Hotez told CNN's Jake Tapper on Tuesday. "So, Houston Independent school district opens August 23. That's going to be a huge accelerant. ... This is just the beginning, unfortunately."
Though the rise in children's cases coincides with the surges among the broader US public since early summer, the proportion of child cases is up. Child cases represented 18% of the US total last week, against 14.4% over the whole pandemic, AAP says.
Health experts had hoped to get a critical threshold of the population vaccinated against Covid-19 in time to get spread under control for the new school year, but only 51% of the population is fully vaccinated.
And with the more transmissible Delta variant accounting now for nearly 99% of cases in the US, the situation is growing particularly dangerous for children, experts said.
They have advocated for children to wear masks in school, but some governors have attempted to ban such requirements.
"Why tie the hands of the public health officials behind their backs? You have two weapons here, one is vaccines, the other is masking, and for children less than 12 that's the only weapon they have," Dr. Paul Offit, a member of the US Food and Drug Administration's vaccine advisory committee, told CNN's Erin Burnett on Tuesday.
Hotez said the US is now at a "screaming level of virus transmission," adding that to really interrupt the spread, 80 to 85% of the population will need to be vaccinated.
Boosters planned for adult mRNA vaccine recipients
On Wednesday, the US surgeon general announced a plan to allow booster shots to any American adult, age 18 and older, who already had received two doses of either the Pfizer/BioNTech or Moderna mRNA vaccines.
That plan still depends on whether the US Food and Drug Administration authorizes boosters and whether the CDC's immunization advisory committee recommends those boosters, US Surgeon General Dr. Vivek Murthy said.
Under the plan, adult mRNA vaccine recipients would be eligible for a booster eight months after receiving their second dose, starting the week of September 20, Murthy said during the White House Covid-19 news conference.
As for the people who received the other Covid-19 vaccine authorized in the US -- the one-dose Johnson & Johnson product -- more data needs to be collected before a booster is recommended for them, Murthy said.
The plan to authorize an mRNA booster comes as data suggests that protection against mild and moderate disease from the first two doses appears to decline over time, Murthy said.
He emphasized coronavirus vaccines still appear to be effective in protecting against severe Covid-19, hospitalization and death.
But, "we are concerned that this pattern of decline we are seeing (in protections against mild and moderate disease) will continue in the months ahead, which could lead to reduced protection against severe disease, hospitalization and death," Murthy said.
On Monday, Pfizer and BioNTech said they submitted initial data to the FDA to support the use of a booster. Their data indicated a booster dose elicited a significantly higher antibody response against the initial strain of coronavirus and the Delta and Beta variants compared to what was seen among people who got two doses.
Last week, the FDA authorized third doses for some people who are immunocompromised, and the CDC almost immediately recommended giving those doses.
As the Delta variant increased its grip in the US this summer, coronavirus cases, hospitalizations and deaths have jumped.
The US averaged more than 137,500 new daily cases over the past week -- an average that is more than 11 times higher than it was two months ago, when the figure was nearing its lowest point of the year, according to Johns Hopkins University.
More than 88,300 Covid-19 patients were in US hospitals Tuesday, nearly five times higher than two months ago, according to the Department of Health and Human Services. And the US averaged 734 Covid-19 deaths a day over the past week, more than double the average seen two months ago, according to Johns Hopkins.
A student is administered a test during a Covid-19 testing day at Brandeis Elementary School on August 17, 2021, in Louisville, Kentucky.
Thousands of students already quarantining
Many schools that have gone back to campus are already seeing the impact of the spread of the virus.
More than 3,000 students and employees have been quarantined in the New Orleans Public School District because of Covid-19 cases in the past week, according to the district's latest tally.
They represent 5.89% of the students and teachers in the district.
Students returned to the New Orleans Public School District on August 12 and are required to wear masks in school facilities, according to the district.
Mask mandates have caused tension in Florida as some schools press to implement them but are going up against Gov. Ron DeSantis' ban against such requirements.
Among the state's 15 largest school districts, at least 4,641 students and 1,547 employees have tested positive for coronavirus and at least another 19,072 students and staff members have been quarantined or isolated because of Covid-19.
The tallies do not include any cases from the two biggest school districts in Florida -- Miami-Dade and Broward. Miami-Dade begins classes August 23. Broward started Wednesday.
On Tuesday, Florida's State Board of Education voted unanimously to recommend investigations into the Broward and Alachua districts over their requirements for mask-wearing in school.
In Arizona, Gov. Doug Ducey said the state would use federal Covid relief money to increase the funding available to public school districts only if they're open for in-person learning and don't require children to wear masks.
A handful of Arizona districts have imposed mask mandates despite the state law that prohibits them, arguing the ban cannot go into effect until mid-September at the earliest, making their current mandates legal.
In Washington, Gov. Jay Inslee announced a policy that requires everyone who works at an academic institution in the state to be vaccinated by October 18.
"We won't gamble with the health of our children, our educators and school staff, nor the health of the communities they serve," Inslee said.
