Advice is evolving along with the coronavirus. Here’s the latest from staff and wire reports.

Where do I need to wear a mask?

Minneapolis and St. Paul renewed mask mandates in city facilities and encouraged people in the Twin Cities, regardless of their vaccination status, to wear them indoors in response to a variant-fueled wave of COVID-19.

Hennepin and Ramsey counties reinstated their mask mandates in county facilities as well.

Target, Cub Foods and other retailers require masks for employees and encouraged them for customers in areas with high coronavirus transmission levels.

Some businesses such as Juut Salon Spa, as well as buildings such as the Capella Tower in downtown Minneapolis, are requiring customers to wear masks again.

An estimated 150,000 unionized workers at the big three U.S. automakers had to go back to wearing masks, while nonunion Toyota, with a U.S. workforce of about 36,000, said it will do likewise at most of its sites across the country.

What about K-12 schools?

The Centers for Disease Control and Prevention recommended that people wear masks in K-12 schools and in counties with high or substantial levels of viral transmission.

State health and education officials are recommending — but not requiring — that Minnesota school districts mandate indoor mask wearing for all students and teachers this fall, whether or not they have received a COVID-19 vaccine.

Because Gov. Tim Walz no longer retains the emergency powers that allowed the state to mandate mask-wearing earlier in the pandemic, decisions about masking, social distancing and other precautionary measures will be left to local school districts. Only two statewide requirements remain: Schools must report all confirmed COVID-19 cases to the state, and students and staff must wear masks while on school buses, in line with federal guidelines for public transportation.

Many school districts have not yet said whether they’ll require masks this fall.

A spokesman for Minneapolis Public Schools said the district will finalize its plans in the next few weeks. St. Paul Public Schools spokesman Kevin Burns said his district will announce its plan Aug. 10.

Anoka-Hennepin Schools, the state’s largest district, will recommend — but not require — that everyone in school buildings wear masks, said district spokesman Jim Skelly.

Guidelines released by the Osseo school district earlier in July said masks would be recommended for anyone unvaccinated, though the district cautioned that its plans could change depending on new recommendations from state or federal health officials. The Elk River district said in mid-July that masks would not be required, and did not make any specific recommendations. Wayzata’s current back-to-school plan says masks are optional, but district officials said they are reviewing the new recommendations and will update families of any changes.

Other districts have specific plans for students too young to be vaccinated. In Duluth, children from age 2 to those attending fifth grade will be required to wear masks, and masks will be recommended for anyone unvaccinated.

In Rochester, school board members voted this week to require people under age 12 to wear masks. Mask wearing is recommended for older students and adults there, regardless of their vaccine status.

What about colleges and universities?

The University of St. Thomas announced a vaccine requirement for students and staff before they return to campus this fall — joining about 600 colleges nationally, including several local institutions.

Hamline University, St. Catherine University, Macalester College, Carleton College, St. Olaf College, Gustavus Adolphus College and the Mitchell Hamline School of Law also will require students to be vaccinated against COVID-19 before returning this fall.

The University of Minnesota said all students, employees and visitors at its five campuses are required to wear masks indoors, regardless of their vaccination status. Minnesota State Chancellor Devinder Malhotra told presidents of the system’s 37 colleges and universities they should reinstate indoor mask mandates if they are located in counties with high virus transmission. Neither of the public college systems is requiring students to be vaccinated, despite growing calls to do so.

How do I get the $100 vaccine incentive in Minnesota?

A reward site offering $100 for new COVID-19 vaccinations in Minnesota debuted as the state continued to show signs of a new variant-fueled pandemic wave.

Roughly $2.5 million in federal funding is available for the new $100 state incentive program, which follows an incentive program earlier this summer that tried to sway people with offers of free fishing licenses or tickets to ValleyFair or other destinations. Fewer than 20,000 people signed up for that incentive program, and most selected $25 gift cards.

The budgeted amount means the new incentive is available to the first 24,330 registrants who sign up by the end of Aug. 15. Gov. Tim Walz said he would work with the Legislature and nonprofit organizations to seek more state or private funding to continue the program as needed.

Are businesses mandating the vaccine?

Some workplace policies are making it more of a hassle for workers to resist the vaccine. Others culminate in unvaccinated employees losing their jobs.

The changes are most prominent in health care, where the number of hospital systems announcing vaccine mandates and other measures jumped from fewer than 100 three or four weeks ago to 800 or more by the end of July, said Akin Demehin, director of policy at the American Hospital Association.

The majority of those employed by Mayo Clinic have been immunized, but the clinic announced that workers throughout the Rochester-based health system must get vaccinated or go through an hourlong education session.

Essentia Health will require all employees to be fully vaccinated against COVID-19 by November. With few exceptions for medical and religious reasons, the mandate applies to all 13,000 of the Duluth-based health system’s employees in Minnesota, Wisconsin and North Dakota.

Sanford Health is requiring all workers to get shots by Nov. 1.

There are signs of growing interest in other sectors as well.

Google and Facebook said that as the tech companies reopen campuses, anyone coming to work must be fully vaccinated. In California and New York City, unvaccinated government workers soon will be subject to routine COVID-19 testing. President Joe Bidenannounced that federal employees who aren’t immunized must undergo testing, wear masks and keep physically distant.

The Federal Reserve Bank of Minneapolis said it will require its 1,100 employees to get vaccinated against COVID-19 by the end of August.

Microsoft, Tyson Foods and the U.S. auto industry joined state and local governments and other major employers that are taking a hard line.

Walmart is requiring that all workers at its headquarters as well as its managers who travel within the U.S. be vaccinated against COVID-19 by Oct. 4.

Concertgoers will have to show proof of full COVID-19 vaccination or negative test results to get into a show at First Avenue or any of its sister venues.

What else are businesses doing?

U.S. Bancorp will wait until later this fall to have corporate employees return to the office, citing a resurgence in coronavirus for delaying its initial plan toend most remote work after Labor Day.

The company is the fifth-largest employer in downtown Minneapolis with nearly 5,000 workers at its corporate headquarters.

Wells Fargo, another large employer in downtown Minneapolis, is sticking for now with its plan to begin to phased return to the office in September.

Who can make you get a COVID vaccine?

Millions of Americans have chosen not to get a coronavirus vaccine. But with the shots readily available and virus cases ticking back up in parts of the country, a growing number of employers, universities and businesses are now issuing some form of a vaccine requirement. (Here’s a look at who could ask you to get the vaccine.)

Under many of these orders, those who remain unvaccinated, including people who can’t get a vaccine because of a disability or conflicting religious beliefs, will instead have to follow strict guidelines like regular COVID testing, masking and social distancing.

“I think probably what these companies are thinking — for those individuals — requiring them to be masked, or constantly tested, is a reasonable accommodation,” Joel Friedman, a law professor at Tulane University, said. “And that’s probably correct.”

Another component of the shifting landscape on vaccines is their expected full approval by the Food and Drug Administration. The vaccines are currently administered under an emergency use authorization, so full approval could alleviate concerns over their safety — and encourage even more organizations to make them a requirement.

Is the delta variant more contagious?

Scientists who studied a big COVID-19 outbreak in Massachusetts concluded that vaccinated people who got so-called breakthrough infections carried about the same amount of the coronavirus as those who did not get the shots.

The research was key in the decision by the Centers for Disease Control and Prevention to recommend that vaccinated people return to wearing masks indoors in parts of the U.S. where the delta variant is fueling infection surges.

Previously, vaccinated people who got infected were thought to have low levels of virus and to be unlikely to pass it to others. But the new data shows that is not the case with the delta variant.

The delta variant, first detected in India, causes infections that are more contagious than the common cold, flu, smallpox and the Ebola virus, and it is as infectious as chickenpox, according to the documents, which mentioned the Provincetown cases.

People with breakthrough infections make up an increasing portion of hospitalizations and in-hospital deaths among COVID-19 patients, coinciding with the spread of the delta variant, according to the documents.

Is the delta variant making younger people sicker?

Physicians working in COVID-19 hot spots across the nation say the patients in their hospitals are not like the patients they saw last year. Almost always unvaccinated, the new arrivals tend to be younger, many in their 20s or 30s. And they seem sicker than younger patients were last year, deteriorating more rapidly.

Doctors have coined a new phrase to describe them: “younger, sicker, quicker.” Many physicians treating them suspect that the delta variant of the coronavirus, which now accounts for more than 80% of new infections nationwide, is playing a role.

Studies done in a handful of other countries suggest that the variant may cause more severe disease, but there is no definitive data showing that the new variant is somehow worse for young adults.

Some experts believe the shift in patient demographics is strictly a result of lower vaccination rates in this group.

“Our sense is that younger, healthier people are more susceptible to the delta variant than those that were circulating earlier,” said Dr. Cam Patterson, chancellor of the University of Arkansas for Medical Sciences.

What does the delta variant mean for herd immunity?

The spread of the delta coronavirus variant has pushed the threshold for herd immunity to well over 80% and potentially approaching 90%, according to an Infectious Diseases Society of America briefing.

That represents a “much higher” bar than previous estimates of 60% to 70%, because delta is twice as transmissible, said Ricardo Franco, an assistant professor at the University of Alabama at Birmingham.

“It is becoming clear that this is a very dangerous, way more dangerous virus than the original one,” Franco said.

Herd immunity is based on the idea that when a certain percentage of the population has been vaccinated against the virus or gains immunity by a previous infection, it helps protect the broader population and reduce transmission.

What about booster shots?

World Health Organization WHO Director-General Tedros Adhanom Ghebreyesuscalled for a moratorium on administering booster shots of COVID-19 vaccines as a way to help ensure that doses are available in countries where few people have received their first shots.

WHO officials say the science is unproven about whether giving booster shots to people who have received two vaccine doses is effective in preventing the spread of the coronavirus.

Israel, France, Germany and many Middle Eastern countries have started administering boosters, and other nations, including the United States and Britain, are considering plans to do so in the wake of the emergence of the highly transmissible delta variant.