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

What's the latest?

Where can I see Minnesota's COVID-19 numbers?

Check our COVID tracker.

Where can I get a vaccine?

Check the state of Minnesota's vaccine page or vaccines.gov.

What's the difference between RSV, the flu and COVID-19?

All three respiratory viruses can have some or all of the same symptoms, including a cough, runny nose, fever or sore throat.

The flu is notorious for quick onset and fatigue and body aches that feel like "you've just been hit by a truck," said Ethan Wiener, chief of the emergency department at NYU Langone's Hassenfeld Children's Hospital.

COVID has a "constellation of symptoms," usually accompanied by headache but not always. It often begins with a sore throat but may also include a cough, fatigue, respiratory symptoms, fever and sometimes tightness in the chest, among other symptoms.

RSV is a common winter virus that usually causes mild, cold-like symptoms that typically appear in stages, not all at once. Symptoms can include runny nose, loss of appetite, coughing, sneezing and wheezing. Some people with RSV may have a fever, but not everyone. In infants, the only symptoms may be irritability, decreased activity and breathing difficulties, according to the CDC. Sometimes, RSV can lead to bronchiolitis, inflammation of the small airways in the lung; and pneumonia, an infection in the lung.

Your pediatrician or family doctor can do a swab test to determine which virus you have. Hospitals also have a single test that can check for all three viruses. The treatment is largely the same: comfort care. Manage fever and pain with ibuprofen or acetaminophen, but the CDC advises to never give children aspirin, which has been linked with a rare condition call Reye's syndrome. Read more here.

What about boosters?

The CDC recommends one booster shot for everyone 5 and up. A second booster is reserved for those age 50 and up or those 12 and older who are "moderately or severely immunocompromised." For more information on boosters such as how long to wait after the primary series, go to tinyurl.com/CDCboosterinfo.

How can I make a COVID-19 vaccine appointment for kids in Minnesota?

Minnesota has a webpage (mn.gov/vaxforkids) to help parents and guardians find a vaccine and answer questions.

Where can I get tested for COVID-19?

Minnesota has several free COVID-19 testing sites that offer saliva and/or rapid tests, although many closed amid declines in testing. Many offer rapid access to antiviral treatment. Health care providers and some pharmacies also offer testing.

Minnesota phased out a mail-in COVID-19 testing program and is now offering free rapid at-home tests. Order your tests here. The federal government has suspended free tests due to lack of funding.

You may find home rapid tests at pharmacies including Walgreens and CVS, grocery stores, health care providers and online. Read more about testing here.

Minnesota health insurers cover the cost of at-home COVID-19 tests, but state officials advise that consumers should contact health plans first to understand how to access the new benefits. Read more here. Insurers will pay up to $12 per individual test, or $24 for a package that contains two tests, and provide coverage for up to eight tests per person per month. UnitedHealthcare has agreements with Walmart and a growing list of retailers to make available free at-home COVID-19 tests when subscribers present their ID cards at pharmacy counters. Minnesotans are finding plenty of gaps and footnotes in coverage.

What if my free tests are expired or about to expire?

Federal regulators on June 7 extended the usefulness of the iHealth rapid antigen tests for three months beyond their listed expiration dates, giving Minnesotans more time to use them.

The three-month extension applies only to the iHealth tests with listed expiration dates no later than Sept. 29. Other tests beyond their permitted expiration dates shouldn't be used, because the chemical and molecular components won't be as effective at detecting the coronavirus that causes COVID-19. Read more here.

What should I do if I've been exposed?

The CDC said anyone exposed — regardless of vaccination status — should get tested five days later, if possible. It said quarantining at home is not necessary, but urged people to wear a high-quality mask for 10 days. Read more here.

If you were exposed to COVID-19 and don't have symptoms, take three home tests instead of two to make sure you're not infected if you test negative, according to new U.S. recommendations.

If you have COVID-19 symptoms, test again 48 hours after the first negative test. If you get a negative result on the second test and you are concerned that you could have COVID-19, you may choose to test again 48 hours after the second test, consider getting a laboratory molecular-based test or call your health care provider. Read more here.

What should I do if I test positive for COVID-19?

The CDC said people who test positive should isolate from others for at least five days, regardless of whether they were vaccinated. If you live with other people, that means staying in a separate room and using a separate bathroom, if possible. You should also wear a mask if you come into contact with others.

You should get care if you have trouble breathing or develop other serious symptoms. But there are many people with certain conditions — including heart diseases, diabetes and weakened immune systems — who should seek care even if they have mild illness, because of their elevated risk for developing serious complications. You should tell your doctor, who may prescribe medications. Tell the people you've been in close contact with.

People with symptoms during isolation, or who develop symptoms during quarantine, are encouraged to stay home.

CDC officials advise that people can end isolation if they are fever-free for 24 hours without the use of medication and they are without symptoms or the symptoms are improving. The CDC said people should wear masks everywhere for the five days after isolation ends.

The CDC cited evidence showing that people with the coronavirus are most infectious in the two days before and three days after symptoms develop.

Can kids who've been exposed to COVID go to school?

The CDC on Aug. 11 ended the recommendation that schools do routine daily testing, although that practice can be reinstated in certain situations during a surge in infections, officials said.

The CDC also dropped a "test-to-stay" recommendation, which said students exposed to COVID-19 could regularly test — instead of quarantining at home — to keep attending school. With no quarantine recommendation anymore, the testing option disappeared too.

Masking mandates were linked with significantly reduced numbers of COVID-19 cases in schools, a new study shows. The so-called natural experiment occurred when all but two school districts in the greater Boston area lifted mask requirements in the spring.

What's going on with Minnesota schools?

The majority of Minnesota students returning to classrooms this fall won't have to wear a mask. Most districts also won't require COVID-19 vaccinations for pupils or educators. Read more here.

Minnesota's health commissioner won't seek to require COVID-19 vaccination for school attendance, even if federal authorities add it to the recommended pediatric immunization schedule.

Minneapolis Public Schools will no longer require employees, contractors or volunteers to get the COVID-19 vaccination or file for an exception.

Is it safe to get the COVID-19 booster and flu shot at the same time?

Yes, experts say. Health care providers should offer flu and COVID-19 vaccines at the same visit to people who are eligible, according to the U.S. Centers for Disease Control and Prevention.

How does getting vaccinated affect the menstrual cycle?

A study of nearly 20,000 people around the world shows that getting vaccinated against COVID can change the timing of the menstrual cycle. Vaccinated people experienced, on average, about a one-day delay in getting their periods, compared with those who hadn't been vaccinated.

What is the Novavax vaccine?

Novavax shots — already used in Australia, Canada, parts of Europe and dozens of other countries — are a protein vaccine that's made with a more conventional technology than the other U.S. options. Protein vaccines have been used for years to prevent other diseases including hepatitis B and shingles.

The CDC on July 19 endorsed the initial two-dose series for people 18 and older. U.S. regulators on Oct. 19 authorized a booster dose of the COVID-19 vaccine made by Novavax.

How do variants work?

At first, SARS-CoV-2 followed the slow and steady course that scientists had expected based on other coronaviruses. Its evolutionary tree gradually split into branches, each gaining a few mutations. Evolutionary biologists kept track of them with codes that made little difference to how sick the viruses made people.

But then one lineage, initially known as B.1.1.7, defied expectations. When British scientists discovered it, in December 2020, they were surprised to find it bore a unique sequence of 23 mutations. Those mutations allowed it to spread much faster.

Within a few months, several other worrying variants came to light around the world — each with its own combination of mutations, each with the potential to spread quickly and cause a surge of deaths. To make it easier to communicate about them, the WHO came up with its Greek system. B.1.1.7 became alpha.

Alpha came to dominate the world, whereas beta took over only in South Africa and a few other countries before petering out. Beta did not descend from alpha. Instead, it arose with its own set of new mutations from a different branch of the SARS-CoV-2 tree. The same held true for all the Greek-named variants, up to omicron.

It's likely that most of these variants got their mutations by going into hiding. Instead of jumping from one host to another, they created chronic infections in people with weakened immune systems. These victims harbored the virus for months, allowing it to accumulate mutations. When it eventually emerged from its host, the virus had a startling range of new abilities — finding new ways to invade cells, weaken the immune system and evade antibodies.

What is the omicron variant?

First identified in Botswana and South Africa in November, the omicron variant surged around the world. Scientists first recognized omicron thanks to its distinctive combination of more than 50 mutations. Some of them were carried by earlier variants such as alpha and beta. Read more here.

All the most significant COVID-19 variations today are descending from omicron. After the original omicron virus evolved in the fall of 2021, its descendants split into at least five branches, known as BA.1 through BA.5. As it spread and caused an unprecedented spike in cases, it drove most other variants to extinction. Over the next few months, the subvariants took turns rising to dominance.

Experts are nervously eyeing a swarm of viruses descended from omicron — and a new evolutionary phase in the pandemic. Multiple versions of the omicron variant — including XBB, BQ.1.1 and BA.2.75.s — threaten to knock out treatments and challenge vaccines this winter.

Does omicron spread faster than other variants?

Yes. Omicron also appears to have a shorter incubation period than other variants do. People who are infected with omicron typically develop symptoms just three days after infection, on average, compared with four days for delta and five days for earlier variants. Read more here.

What is "long COVID" and how many people get it?

Long COVID is the term used to describe an array of symptoms that can last for months or longer after the initial coronavirus infection. Researchers in a large CDC study identified post-COVID health problems in many different organ systems, including the heart, lungs and kidneys. Other issues involved blood circulation, the musculoskeletal system and the endocrine system; gastrointestinal conditions, neurological problems and psychiatric symptoms were also identified in the study.

In a 2021 study, more than half of American adults reported symptoms of major depressive disorder after a coronavirus infection. Read more here.

One in five adult COVID survivors under age 65 in the U.S. has experienced at least one health condition that could be considered long COVID, according to the study. Among patients 65 and older, the number is even higher: one in four. Read more here.

A new Scottish study on long COVID based on the experiences of nearly 100,000 participants found that six to 18 months after infection, one in 20 people had not recovered and 42 percent reported feeling only somewhat better.

Brain and nerve conditions such as Alzheimer's disease and stroke are significantly more common among COVID-19 survivors than those who've never had the disease, according to a study of millions of patient records.

People with mild or moderate initial coronavirus infections can still experience debilitating post-COVID symptoms. 76% of Americans diagnosed with long COVID were not sick enough to be hospitalized for their initial infection, a new study found. Two-thirds of the patients had preexisting health conditions, but nearly one-third did not. Read more here.

Scientists are racing to pinpoint long COVID's cause. Momentum is building around a few key theories. One is that the infection or remnants of the virus persist past the initial illness, triggering inflammation. Another is that latent viruses in the body, such as the Epstein-Barr virus that causes mononucleosis, are reactivated. A third theory is that autoimmune responses develop after acute COVID-19. Another possibility is that tiny clots play a role.

There is fresh evidence that vaccination may reduce the chances of developing long COVID.

What's going on with Johnson & Johnson shots?

U.S. regulators on May 5 strictly limited who can receive Johnson & Johnson's COVID-19 vaccine due to the ongoing risk of rare but serious blood clots. The FDA said the shot should be given only to adults who cannot receive a different vaccine or specifically request J&J's vaccine.

Can I get a vaccine incentive?

Those programs have ended.

What does the CDC say about masks?

Most Americans live in places where healthy people, including students in schools, can safely take a break from wearing masks under new U.S. guidelines. Read the CDC's latest advice here.

Travelers no longer have to wear face masks at Minneapolis-St. Paul International Airport or while riding Metro Transit trains and buses. A federal judge in Florida threw out a national mask mandate for public transportation across the U.S. The ruling gives airports, mass transit systems, airlines and ride-hailing services the option to keep mask rules or ditch them entirely, resulting in rules that vary by city and mode of transportation.

Americans age 2 and older should wear a well-fitting masks while on public transportation, including in airports and train stations, the CDC recommended May 3, citing the current spread of coronavirus and projections of future COVID-19 trends.

An uptick in COVID-19 activity prompted the city of Minneapolis on April 28 to recommend public indoor mask wearing again.

Should I still wear a mask?

Lab researchers have found that various types of face masks, including cloth masks, surgical masks and N95 respirators, help prevent the spread of the coronavirus. Read more about the science of masking to help you make decisions about if, when and where to cover your face.

How can I get a quality face mask (and avoid counterfeits)?

There are so many different masks for sale, it's tough to know which ones have been tested and certified by government agencies, and which are counterfeit. Read a guide to choosing the best mask for you here.

Can I get a free N95 mask?

The Biden administration is making 400 million N95 masks available for free to U.S. residents. Read more on finding them here.

Should you mix or match your COVID-19 vaccine booster shot?

Most Americans should be given the Pfizer or Moderna vaccines instead of the Johnson & Johnson shot that can cause rare but serious blood clots, U.S. health officials said Dec. 16.

How often do COVID vaccines cause heart problems in kids?

While the COVID-19 vaccines made by Pfizer-BioNTech and Moderna do seem to be associated with an increased risk of myocarditis, the latest data indicate that the absolute risk remains very small and that most cases are mild and resolve quickly. Read more here.

Do masks work?

Ordinary surgical and paper masks work when worn properly, said Chris Hogan, a University of Minnesota researcher who has studied mask effectiveness and is editor of the Journal of Aerosol Science.

Generally, the CDC says masks should "fit snugly over your mouth, nose and chin."

If you decide to keep wearing your multi-layer homemade or cloth mask, experts advise washing them every day. But proceed with caution. Read more here.

What about N95s?

Masks are best at keeping your exhaled particles away from others. Respirators, like the N95, also keep others' particles away from you. Any bona fide N95 has been certified to filter at least 95% of particles.

Many doctors and public health experts are now advocating for their use among the general public. Early in the pandemic, people were discouraged the masks over fear there wouldn't be enough for health care workers. That's no longer the case. Read more about N95 and KN95 respirators here.

How does pregnancy affect immunity?

Pregnant women who are vaccinated are nearly twice as likely to get COVID-19 as those who are not pregnant, according to a new study, and have the greatest risk among a dozen medical states, including being an organ transplant recipient and having cancer.

Dr. David R. Little, a researcher at Wisconsin-based Epic, said the findings buttress CDC recommendations that additional precautions against the virus should be taken during pregnancy, such as wearing masks and maintaining safe distances. Read more here.

COVID-19 drove a dramatic increase in the number of women who died from pregnancy or childbirth complications in the U.S. last year, a crisis that has disproportionately claimed Black and Hispanic women as victims, according to a government report.

COVID-19 drove a dramatic increase in the number of women who died from pregnancy or childbirth complications in the U.S. last year, a crisis that has disproportionately claimed Black and Hispanic women as victims, according to a government report.

Should pregnant women get the vaccine?

The CDC urged all pregnant women to get the COVID-19 vaccine as hospitals around the U.S. see disturbing numbers of unvaccinated mothers-to-be seriously ill with the virus. Expectant women run a higher risk of severe illness and pregnancy complications from the coronavirus.

A research study based on data from Bloomington-based HealthPartners and medical centers across the country finds that pregnant women who received COVID-19 vaccines did not experience an increased risk of miscarriage.

If you're thinking of getting pregnant, there's no evidence that any vaccines, including COVID-19 vaccines, influence your chances of getting pregnant despite a myth suggesting otherwise.

Do pregnant women who get vaccinated pass the protection to their babies?

COVID-19 vaccines during pregnancy can protect babies after they're born and lead to fewer hospitalized infants, a new U.S. government study suggested.

What if I'm going to Canada?

Canada is dropping the vaccine requirement for people entering the country, and will no longer require people to wear masks on planes, starting Oct. 1. See CDC travel guidelines here. The Public Health Agency of Canada still strongly recommends that people wear masks, particularly in crowded environments such as planes and trains.

What about other countries?

After two years of warning travelers to avoid visiting a very long list of countries deemed to be "high risk" for coronavirus infection, the CDC has dropped them all from its list. Read more here.

Are the vaccines safe?

A review of 6.2 million vaccine recipients in Minnesota and seven other U.S. regions found no significantly elevated rates of conditions such as stroke or heart attack immediately following COVID-19 vaccination. Bloomington-based HealthPartners participated in the study, which looked for elevated rates of 23 potential side effects in the first three weeks after people received Pfizer or Moderna COVID-19 vaccines.

Who qualifies for an extra shot?

Federal officials approved an extra dose for those undergoing cancer treatment, who've received organ transplants or had other conditions that depress the body's immune system. These doses are not considered to be boosters.

Can kids get long COVID?

Yes, but studies indicate they're less likely than adults to be affected by symptoms.

A U.K. study found about 4% of young children and teens had symptoms more than a month after getting infected. Fatigue, headaches and loss of smell were among the most common complaints and most were gone by two months. Coughing, chest pain and brain fog are among other long-term symptoms sometimes found in kids, and can occur even after mild infections or no initial symptoms.

Some studies have found higher rates of persisting symptoms than in the U.K. study.

Kids can develop other rare problems after a coronavirus infection, including heart inflammation or a condition known as multisystem inflammatory syndrome. Because of the potential for long-term consequences, the American Academy of Pediatrics recommends follow-up doctor visits after children recover from an initial coronavirus infection.

What is the Docket app?

Minnesota introduced the Docket app for viewing personal immunization records in response to rising demand — largely because of COVID-19 vaccination requirements by employers and organizations.

Correction: Previous versions of this story incorrectly described the Ramsey County Deputies’ Federation’s stance on a proposed COVID-19 vaccine mandate for county employees. Previous versions of this story incorrectly stated the Capella Building requires masks.