(CNN) When Perrysburg School Superintendent Thomas Hosler sent a survey to parents in his Toledo-area district to see how many wanted to get their children vaccinated against Covid-19, he got more than 20,000 "no" responses. His district only has 5,700 students in it.
"Clearly someone spent a lot of time in their basement working hard to invalidate our survey," Hosler said. "That gives you an idea of how people are reacting to pandemic decisions. This year, for our teachers especially, it feels a lot more stressful and we're only in November."
The questioning of district policy has "really ramped up" he said, particularly over one issue: masks.
Hosler's is one of 65% of Ohio school districts that, according to the state's department of education, have dropped mask mandates as cases have declined significantly.
"No matter what decision we make, there's going to be a loud vocal reaction opposed to it," Hosler said. "It's a little bit liberating in a sense, because we're going to go ahead and make the best decision for kids to keep them safe."
While studies show that masks in school work, whether a child has to wear a mask at school at this point in the Covid-19 pandemic depends largely on where they live in the country.
The US Centers for Disease Control and Prevention guidelines have not changed.
Due to the highly contagious Delta variant, the CDC guidelines recommend everyone -- students, staff, teachers and visitors to K-12 schools -- wear masks indoors, regardless of vaccination status. The American Academy of Pediatrics makes a similar recommendation. Yet hundreds of districts around the country made masks optional, according to a CNN analysis of school records.
Masks are still mandatory in states including Illinois, California, New York and Washington. Washington state even promised to withhold money from districts that don't comply. In those and many other states, parents have staged large protests and sued districts over mask mandates, leaving school leaders with tough choices about how to best keep kids safe.
Some, but not all, schools in Georgia, Louisiana, South Carolina, Tennessee, Kentucky and Ohio have made masks in schools optional, often citing declines in Covid-19 cases. In Texas, schools aren't even allowed to require masks, although some districts, including Dallas, have ignored the state and kept the mandates. There's a federal investigation to determine if the Texas prohibition on mask mandates is impinging on the rights of students with disabilities.
In Perrysburg, Hosler said his district's mask policy has changed with case numbers. It started the year with a "mask strongly encouraged" policy because cases were low and the vaccination rate in the area was high. Three days into the new school year, there were signs the district needed to do more.
"We saw this increase in cases and we saw it with the younger students, which we really hadn't seen the year before," Hosler said.
By the second week of school, he made masks mandatory. A couple of weeks ago, after it seemed like the case numbers had fallen again, he made masks optional again. He said his decision was aided by an October state policy change that allowed kids who were exposed to Covid-19 at school to stay in class if they wore a mask. "That opened the door to keeping kids in school," he said. "So that's what led us to the decision to go mask optional."
Even with the mask optional policy, about 70% of his students still wear them, he said. The numbers are lower among high school students.
"We're watching the cases closely," Hosler said. "We've already made adjustments and we're prepared to make another adjustment if needed."
Each time the mask policy has changed, he said, he has gotten both pushback and praise. It's similar to when he makes a decision about closing the school for a snow day.
"This kind of decision is like that one on steroids," Hosler said. "No matter what decision we make, there's going to be a loud vocal reaction opposed to it and people are going to be angry."
In Fulton County, Georgia's fourth largest school district, Superintendent Mark Looney decided masks could be optional if the district met one of two benchmarks. One is if the ratio of cases in a school remains less than 1% of students enrolled. The second benchmark is 30 days after vaccines are approved for children over 5 years old, regardless of vaccination status of the students.
"We've learned a lot from managing Covid for almost two years now," Looney said. "The number of Covid cases appears to have peaked and has been trending down since early September. We think that we've weathered most of the storm."
There is still an option to change the policy if conditions make that necessary, Looney said.
In Massachusetts, about 35 miles west of Boston, the Hopkinton High School Committee voted 3-2 to allow a three-week trial period eliminating mask requirements for those students who were vaccinated. Unvaccinated students still have to wear masks.
Since the vaccination rate at the school is 80%, the district was allowed to make the change under the Commonwealth's policy. This is a trial period for now. The district is bringing mandates back November 22 in anticipation of the Thanksgiving holiday and travel. The board could also vote the policy back in if cases rise. So far, no new positive cases have been reported.
Washington state has kept its mask mandate for all schools and any district that "willfully" violates state health requirements risks losing state funding.
Washington Secretary of Health Dr. Umair Shah said masking is a critical piece to protect kids and keep them in school when community transmission remains "higher than any of us would like."
"Masks work, in addition to other modalities," Shah said. Masks, handwashing, vaccinations, and the appropriate physical distancing can be used to keep kids in class. "Kids want to be around each other, and we found that all of those precautions need to come together," he said.
Shah said he knows these mitigation factors work because, while schools have had some outbreaks, Washington has been "markedly better" than comparable states in the country.
"We all recognize we want to be past this pandemic," Shah said. "but to keep them in school, it's really up to us to make sure that we have as many precautions in place to help keep them safe and protected."
When there are multiple layers of protection in place -- physical distance, handwashing, vaccines and masks -- it reduces the transmission of Covid-19, the CDC says.
Studies that specifically look at masks show that outbreaks are far more likely in schools that don't require students and staff to wear masks, according to CDC studies from September. One study in Arizona showed that schools with no masking requirement were about 3.5 times more likely to have a Covid-19 outbreak than schools that had a universal masking requirement.
A second CDC study showed counties across the US where schools required mask use had less transmission of the virus in the community.
Another preprint study, meaning it's not yet peer-reviewed, showed that masks reduce transmission by about 50%. The study was done predominantly in adults, said study co-author Joseph Lewnard, but he said there are some lessons here that can apply to children.
"We found the benefit of mask wearing are greatest to people who are not yet fully vaccinated and that's where most kids find themselves today," said Lewnard, an assistant professor of epidemiology at the University of California Berkeley's School of Public Health.
According to the CDC, 87% of the US population lives in a county that currently has a high or substantial level of transmission. Cases are declining, and more children are getting vaccinated, but until many more are vaccinated, Lewnard thinks masks are a good idea.
"The benefits of mask wearing might be the greatest among this population where you still have a potentially volatile situation when you consider kids, a lot of their interactions, are really occurring with people their same age who also aren't vaccinated. They are kind of in the same place adults were last year before vaccines," he said.
Covid-19 cases are down across the country, yet cases among kids are still considered "extremely high," according to the American Academy of Pediatrics. They make up a disproportionate number of cases -- about a quarter of all total US cases.
It's still less likely for children to be hospitalized with Covid-19 compared to adults and less likely for them to die, but long Covid also occurs in about 4-6% of children. Many of those cases were mild to start. Plus, Covid-19 can be fatal for children, even those without underlying health conditions.
At least 897 children have died from Covid-19 in the United States since the start of the pandemic, according to the CDC.
Dr. Richina Bicette-McCain, an associate medical director at Baylor College of Medicine, said she's watched the end of mandatory mask policies with unease.
"It definitely worries me. I think we are jumping the gun a little bit," Bicette-McCain told CNN's Jake Tapper. "We saw this happen in June over the summer when we declared the pandemic to be over a bit too early. We decided that those who are vaccinated need not wear masks, which turned into everyone not wearing masks and then subsequently the spike and the Delta wave followed."
Dr. Claudia Hoyen, the director of pediatric infection control at UH Rainbow Babies and Children's Hospital in Cleveland, thinks that since there is so much contact with kids throughout the day, it probably makes sense to keep masking.
"We know that indoor contact is the highest risk," said Hoyen. "Whether you're vaccinated or not, it doesn't mean you can't be infected."
Hoyen understands most people don't love wearing a mask, but she thinks kids get why they should.
"A lot of kids know that it's going to keep them safe and it's going to keep them in school and those are the things that they really want," Hoyen said. "You know, for a lot of kids, it's not as big a deal."
Hoyen said with it getting colder outside and people spending even more time indoors, it might be safer to keep mandatory masking in place at least through the end of the year.
"Giving them consistency and expectations can be helpful," Hoyen said. "Masks are working. People are doing OK. Just move forward with them until it gets a little further down the line."
Dr. Anthony Fauci, who thinks masks have helped keep cases down in school, is confident kids won't have to wear them forever.
"No doubt masks make a difference," Fauci, who is director of the National Institute of Allergy ad Infectious Diseases, said on CNN's New Day. "Vaccinations are going to really make a big, big difference. I think a combination of these things, hopefully sometime in the future, we cannot only get the kids back to school, but we can get rid of the masking situation. We have got to do it in a step-by-step fashion."