CNN  — 

While many colleges and universities are offering classes online, that hasn’t necessarily stopped students from gathering. And now some college towns are grappling with outbreaks of Covid-19 as the start of the fall semester complicates local responses to the pandemic.

“We are urging students to understand the imperative role that they play in stopping this community spread and, ultimately, saving lives,” said Mayor Aaron Stephens of East Lansing, Michigan, where Michigan State University students were asked to quarantine after the local health department reported 342 new cases among people affiliated with the university since August 24.

The outbreak started as students returned to East Lansing for the fall semester, the health department’s statement said. MSU resumed classes on September 2. And while most are online, many students had “binding off-campuses leases or simply desired to physically return to the university community.”

“MSU is committed to doing everything we can to prevent the spread of COVID-19,” MSU Physician David Weismantel said. “The safety of our entire community is a priority and we all have a role to play in preventing the spread of the virus.”

Kelly Girtz, the mayor of Athens-Clarke County, Georgia – home to the University of Georgia – told CNN Saturday his city has seen a “dramatic spike” in cases after maintaining lower case counts and death counts throughout the summer. UGA classes began August 20.

“Clearly it’s the return to campus of large numbers of students who are not here through the summertime,” he said.

“Certainly young people are going to do the things that young people do, so we need to create the underlying conditions that keep people safe,” Girtz said, calling for better coordination among state and national leaders. “So that means very low allowance of gatherings and really as much digital or online learning as possible.”

Six students at Miami University in Ohio were cited after holding a house party even though at least one of them tested positive for Covid-19, according to police records. The university declined to comment, citing federal privacy laws, but said students would face disciplinary action if they violate quarantine orders or the city ordinance on mass gatherings.

Arkansas reported a record high of 1,107 new cases on Friday, and Gov. Asa Hutchinson said a backlog in testing was to blame. About 13% of the state’s cases were attributed to young people in college communities, according to Dr. José Romero, secretary of the Arkansas Department of Health – though he said that was down from previous counts, calling it a “good indicator.”

More than 6.4 million infections have been recorded in the US and 193,482 people have died, according to data from Johns Hopkins University.

Air pollution from wildfires could lead to vulnerability

Doctors warn that bad air quality stemming from smoke produced by the wildfires ravaging Western states could make people more vulnerable to coronavirus infections.

“Multiple studies have shown a correlation between higher levels of pollution in the air and greater spread and severity of Covid-19 cases,” said Dr. Brad Spellberg, chief medical officer of the Los Angeles County-USC Medical Center, citing several studies conducted in the United States, China and Italy. “Some studies have also shown that exposure of lung tissue to pollution may increase susceptibility to viral infections.”

Smoke from wildfires can irritate the lungs and cause inflammation that can affect the immune system, said Dr. Rekha Murthy, an infectious disease specialist at Cedars-Sinai Hospital in Los Angeles. That inflammation can make people more at risk of lung infections.

“Whenever the lining of the lung or the airways become inflamed or damaged, it increases the potential for inhaled viral particles to take hold in the lungs and cause infection,” Murthy said.

There are also concerns that smoke-filled air will drive coronavirus-positive people indoors, CNN medical analyst Dr. Leana Wen said. That, she said, could potentially increase the spread of the virus.

“We know being outdoors versus indoors reduces the rate of transmission … but now people are being told you have to go indoors because you don’t want to breathe in the air that could cause respiratory issues,” she said. “But you don’t want to be indoors with other individuals and have a higher rate of contracting COVID-19… so, it’s really a catch-22.”

To prevent the possible spread of coronavirus during the intense fire season, those remaining indoors due to poor air quality should stay away from anyone who is not in their immediate household, Wen said.

Early mask wearing would have saved lives

About 150,000 of the lives lost would have been saved if more Americans wore masks earlier on in the coronavirus pandemic, a health expert says.

“If the President had said from day one everyone is wearing a mask, we’d have about 45,000 deaths in this country,” said CNN medical analyst Dr. Jonathan Reiner, a cardiologist and professor of medicine at George Washington University.

Reiner pointed to how Germany handled the pandemic.

“They haven’t been the best. They haven’t been the worst. They’ve been OK in their pandemic response and they’ve had about 10,000 deaths,” he told CNN’s Erin Burnett.

The US has four times the population of Germany. “So we’d have about 45,000 deaths in this country,” he said. “So about 150,000 people would be alive.”

He reiterated the importance of embracing masks.

“If you want to think about why we still have 40,000 cases a day and 1,000 deaths a day in this country, it’s because we’re still talking about masks,” Reiner said. “It’s so basic.”

More deaths predicted if people let their guards down

An influential model is predicting a catastrophic winter with a significant rise in coronavirus deaths.

A possible scenario sees 415,090 Covid-19 deaths by January, the Institute for Health Metrics and Evaluation (IHME) at the University of Washington says in its latest forecast. The worst-case scenario is 611,000 deaths by January 1.

“When we look ahead into the winter with seasonality kicking in, people becoming clearly less vigilant, you know mask use is down, mobility is up in the nation, you put all those together and we look like we’re going to have a very deadly December ahead of us in terms of toll of coronavirus,” IHME director Dr. Christopher Murray told CNN’s Anderson Cooper.

Despite the dire prediction, President Donald Trump says the US has done “really well” in fighting the virus.

“I really do believe we’re rounding the corner and the vaccines are right there, but not even discussing vaccines and not discussing therapeutics, we’re rounding the corner,” Trump said.

Speaking with MSNBC’s Andrea Mitchell on Friday, Dr. Anthony Fauci said he does not agree with the President’s statements.

“We’re plateauing at around 40,000 cases a day, and the deaths of around 1,000,” said Fauci, the director of the National Institute of Allergy and Infectious Diseases.

He said test positivity is increasing in some regions of the country and people are spending more time indoors because of cooler weather.

“That’s not good for a respiratory-borne virus,” he said.

Fauci warned that the country needs to get the levels down lower “so that when you go into a more precarious situation, like the fall and the winter, you won’t have a situation where you really are at a disadvantage right from the very beginning.”

CNN’s Ray Sanchez, Harmeet Kaur, Amir Vera, Ben Tinker, Maggie Fox and Shelby Lin Erdman contributed to this report.