Maine is not expected to adjust its new mask guidance for those who live in counties where high or substantial transmission exists, even though those designations might fluctuate daily and possibly create confusion.

Instead, Mainers will have to check the Maine Center for Disease Control and Prevention website each day for current information about which counties are transmission hot spots where masks should be worn indoors.

“The state websites will be updated on a daily basis following any changes in the county risk designations from the U.S. CDC, and we encourage Maine people to visit them,” Maine CDC spokesman Robert Long said in an email. “U.S. CDC county risk designations for Maine will also be available by contacting 211 Maine, or calling 1-888-445-4111.”

“In the meantime, with an increase in the daily case count, like that experienced by the rest of the country, we continue to strongly urge all Maine people to get vaccinated, particularly given the threat of the delta variant,” he continued. “Over the past week, we have seen an increase in the daily rate of vaccinations, which we welcome because vaccinations are the best and most effective path to fully emerge from the pandemic.”

Cases – as well as hospitalizations and deaths – have been rising in all states, due in large part to the highly transmissible delta variant, stalling vaccination rates and the resumption of pre-pandemic indoor gatherings.

Maine health officials reported 120 new cases of COVID-19 on Thursday, the highest single-day total since the tail end of the spring surge in late May. No additional deaths were reported.

Nationally, rising case numbers prompted the U.S. CDC this week to update its guidance and ask individuals in areas of high or substantial transmission to resume wearing masks indoors regardless of vaccination status. Gov. Janet Mills announced Wednesday that Maine would adopt that guidance but would not mandate masks again at this time.

Already, though, the new CDC guidance has created challenges. Prior to Mills’ announcement, two counties – York and Piscataquis – had substantial transmission, which is defined as at least 50 cases per 100,000 people over the most recent seven-day period. Later Wednesday afternoon, when the U.S. CDC updated its county data, York and Piscataquis were no longer seeing substantial transmission, but Waldo County was.

With the addition of Thursday’s cases in Maine, Somerset County appears to have reached the level of substantial transmission, based on U.S. CDC standards. However, the federal agency was not listing Somerset County in that category Thursday night. Piscataquis, meanwhile, dropped back to low transmission just two days after being in the substantial category. Piscataquis County has the smallest population of any county in the state so a one-day spike or dip in cases carries more weight.

Since county data can change daily, it’s likely to be challenging for Maine residents to keep up and know in which parts of the state masks are recommended.

For instance, if Kennebec County were to add at least 11 cases on Friday, it would move into substantial transmission. If six new cases emerge in Hancock County, it also would be in that category.

Asked Wednesday why the state didn’t simply adopt a statewide recommendation, Maine CDC Director Dr. Nirav Shah said the state wants to balance “giving people advice based on the risk in their area and not making them feel like the vaccine they got was for naught.”

Long, the agency spokesman, did not answer a question Thursday about whether the state was reconsidering the county-level, rather than a statewide, approach.

Rachael Piltch-Loeb, preparedness fellow at the Harvard T.H. Chan School of Public Health, said the federal guidance this week creates challenges for states.

Some states, she said, will likely ignore the guidance entirely, while others might look for ways to bring back mandates, if not statewide then in virus hotspots. States like Maine, which have simply said they are adopting the U.S. CDC guidance, are in the middle.

“It’s uniquely challenging because the measures can vary from day to day,” Piltch-Loeb said. “I think you’re dealing with people who already have extreme fatigue around the pandemic, and this doesn’t help that.”

There is also a question of how much practical impact the new guidance will have, since it’s not a mandate. Unvaccinated individuals have been advised to wear masks indoors and in crowded areas for many weeks now, but covered faces have become rare sightings in public as the summer progresses.

The seven-day daily case average now sits at 70 in Maine, up from 30 cases two weeks ago and from 24 this time last month, according to data from the Maine CDC. Since the pandemic began, there have been 70,261 confirmed or probable cases of COVID-19 and 899 deaths. Both are among the lowest per capita of any state.

As of Thursday, 40 people were hospitalized in Maine with COVID-19. Of those, 15 were in critical care and nine were on ventilators. Maine had been holding steady on hospitalizations for about a month but has had an increase over the last week. The rate of hospitalization remains far lower than during the spring surge, when on most days more than 100 people were hospitalized.

As of Thursday morning, 67 percent of all U.S. counties were seeing either high or substantial transmission and people there are advised to wear masks indoors. In some states, mostly in the south, nearly all counties are in those categories.

Reaction to the new guidance on masks was diverse among people out and about in Lewiston on Thursday.

“I think masks are a good thing because by wearing one you protect yourself and everyone around you. But I don’t really wear a mask anymore because I feel protected by my vaccine,” said Abdoul-Kader Isman, 40, Lewiston. “If they mandate one, then I will wear one.”

Christopher English, 42, said he supports mask wearing but doesn’t want to go back.

“I don’t feel comfortable with being told to wear a mask now that I am vaccinated,” he said. “But on the other side, if the community decides that’s what we need to do then I can be convinced. But it should really be at the community level. It’s tough, we are in a tough spot.”

Jason Weymouth, 45, said he’s against both mask mandates and vaccines.

“I’ve done my research on what’s in the vaccine. MRNA, proteins, nanoparticles, it’s pretty bad and people just don’t know,” he said. “I’ll wear a mask when I’m supposed to, but I believe in the Constitution and the Bill of Rights, and I feel what’s going on right now is a disgrace.

Others said putting a mask back on is a small ask.

“I’m fully vaccinated, but I don’t know if that’s the case for everyone around me and personally it would devastate me if somehow I transmitted COVID to someone with a compromised immune system,” said Lynnea Hawkins, 41, of Lewiston. “It’s just safer, and with the delta variant going around. I’m on the school committee and I’ve seen the numbers going up. Yeah it sucks, but it’s sadder if people die.”

James Chute, 71, said wearing a mask inside again doesn’t bother him.

“This is not unexpected to me, with the rising caseloads throughout the nation,” he said. “But I’m not responsible for people making unwise decisions about their own health. I have to take care of my own health, my family and friends. If other people want to roll the dice, then they can roll the dice.”

Piltch-Loeb, the public health expert at Harvard, said bringing back masking is certainly prudent from a public health standpoint, even if it’s unpopular.

“I think we maybe unmasked too quickly,” she said. “Frankly, the change in mask expectation should have been tied to a level of vaccination, which many places still haven’t reached. Just because we have a public health tool – vaccines – doesn’t mean we drop all the others.”

Piltch-Loeb said the impact of bringing back mask recommendations might not be widespread, but that doesn’t mean it’s meaningless either.

“I think the lifting of the mask policy was meant to incentivize people to get vaccinated, which I get, but it shifted the social norm so that both vaccinated and unvaccinated stopped wearing masks,” she said. “Choosing to wear a mask again as a vaccinated person helps establish a social norm and reminds us that this is not an individual effort but a population effort.”

Maine remains stuck at just over 60 percent of residents fully vaccinated, and about 68 percent of those age 12 and older who are eligible. The state ranks third behind Vermont and Massachusetts for states with the highest rate, but it hasn’t moved much over the last month.

Still, health officials continue to urge people who have not yet been vaccinated to consider doing so.

“The most important thing that has not changed is the role of vaccines in getting us out of this pandemic,” Shah said Wednesday.

Staff Writer Johnny Liesman contributed to this report.