ROYAL OAK, Mich. -- Michigan has become the national hot spot for covid-19 infections and hospitalizations at a time when more than half the U.S. adult population has been vaccinated and other states have seen the virus's spread diminish substantially.
Doctors, other medical professionals and public health officials point to a number of factors that explain how the situation worsened in Michigan. More contagious variants, especially the mutation first discovered in Britain, have taken root in Michigan with greater prevalence than in other states. Residents have emerged from lengthy state restrictions on dining and crowd sizes and have abandoned mask wearing and social distancing, especially in rural, northern parts of the state that had largely avoided severe outbreaks.
In addition, the state has had only an average vaccination rate.
Michigan has recorded 91,000 new covid-19 cases over the past two weeks, the highest number in the nation, despite improvements in the numbers in recent days. By comparison, that is more cases than California and Texas had combined in the same period.
Beaumont Health, a major hospital system in Michigan, recently warned that its hospitals and staffs had hit critical capacity levels. Covid-19 patient numbers across the eight-hospital health system jumped from 128 on Feb. 28 to more than 800.
"A year ago, the phrase was tsunami," said Dr. Paul Bozyk, assistant chief of critical care and pulmonary medicine at Beaumont Royal Oak. "It was chaotic. People were overwhelmed with what they were seeing: death and dying. This year, it's more of a slow, rising flood. No big surge of patients, but we keep getting more each day. We're full."
Detroit was an early epicenter a year ago when the virus first arrived in the U.S., prompting aggressive measures by Democratic Gov. Gretchen Whitmer to stop the spread. That made her a target of then-President Donald Trump and right-wing protesters who vilified her as the epitome of government overreach in a year when Michigan played a pivotal role in the presidential election.
Toni Schmittling, a nurse anesthetist who works at Sinai-Grace Hospital in Detroit, said that when the city was hard-hit and her hospital had to double up ventilator patients in one room, the rest of Michigan was wondering why restrictions were needed.
"We'd say: 'Are you kidding me? People are dying right and left here,'" Schmittling said.
Now, cases are more spread out, and rural areas are getting hit hard.
Dr. Mark Hamed, medical director in the emergency department at McKenzie Hospital in Sandusky, Mich., and for several counties in the state's northern region, said the area was spared from rampant covid-19 spread last year and that it may have created a false sense of security, especially among the region's farmers and blue-collar workers who suffered economically from the pandemic and already were feeling covid-19 fatigue.
Now, with variants spreading and many people still unvaccinated, his area "is being hit pretty hard," Hamed said. "Our ER is absolutely swamped beyond belief."
The current surge has left medical staffs beleaguered. Unlike their colleagues in other states where the virus is relatively under control, Michigan doctors and nurses are enduring another crisis -- more than a full year after the hospitals in Detroit were besieged.
"We start to gain some hope when the plateau hits, and then here we are with another surge," said Lizzie Smagala, a registered nurse in Beaumont Royal Oak's intensive care unit. "I think the people on the outside of our situation don't understand the depths of what we're going through, how long we've been going through it here in the hospital, and that covid's not really ever left."
But unlike in previous surges, it now is younger and middle-aged adults -- not their parents and grandparents -- who are taking up many of Michigan's hospital beds. Michigan hospitals are admitting about twice as many coronavirus patients in their 30s and 40s as they were during the fall peak, according to the Michigan Health & Hospital Association.
The shifting demographics come as a majority of Michigan residents age 65 or older have been fully vaccinated, greatly reducing the risk to the most vulnerable and leading to fewer hospitalizations among the oldest age groups.
But the vaccinations of older people do not explain rising hospitalizations among people younger than 60, including those in their 20s and 30s. Public health experts say the outbreak -- driven by the B.1.1.7 variant of the virus, which is more contagious and more severe -- is spreading rapidly in younger age groups.
"I am putting more patients in their 20s and 30s and 40s on oxygen and on life support than at any other time in this pandemic," said Dr. Erin Brennan, an emergency room physician in Detroit.
With about two-thirds of the country's oldest residents fully vaccinated, younger adults, many of whom only recently became eligible for the shots, now make up a higher share of total hospitalizations. But the number of people in their 30s and 40s hospitalized with covid-19 nationally has also increased somewhat since March, according to recent CDC data, with a more significant rise for people in their 50s. Hospitalizations among younger people have been up most notably in the Great Lakes states, with rises seen as well in the Mid-Atlantic.
The director of the Centers for Disease Control and Prevention, Dr. Rochelle Walensky, was among those who warned that more younger adults were going to hospitals with severe forms of covid-19. The B.1.1.7 variant -- first identified in Britain and now the most common source of new infection in the United States -- is believed to be about 60% more contagious and 67% more deadly than the original form of the coronavirus.
Public health experts attribute the hospitalizations among younger people to a number of factors, including the B.1.1.7. variant and the lifting of pandemic restrictions around the country. Younger people are among those most likely to be out socializing and in the workforce.
Some health experts said it was conceivable that more younger people were being hospitalized because some hospitals had lowered their standards for admission.
But at Beaumont Royal Oak, in suburban Detroit, where case numbers remain high, doctors said they had not lowered the bar for admissions. The younger people in their care often had fewer chronic health problems and a good chance to recover, but they exhibited serious symptoms that required immediate intervention.
"Some of them have kids that are younger than my kids, and you think about these people and the circumstances for their family if they don't survive," Dr. Felicia Ivascu said.
Dr. Olusola Ogundipe, an infectious disease fellow, said he noticed that some of his younger patients also had a tougher time emotionally with their conditions.
"They have a feeling of immortality," he said, "and so I think it does take younger people by surprise."
At the same time, vaccine hesitancy has been an issue in Michigan. About 40% of the state has received at least one vaccine dose -- about the same as the national average. About 28% of residents 16 and older in Detroit have received at least one dose of vaccine. The city is planning to go door to door to urge people to get vaccine doses -- many of which are manufactured in Michigan at Pfizer's plant near Kalamazoo.
Covid-19's toll in Michigan has been much more than emergency rooms and ICU departments packed with the ill while thousands of people self-quarantine out of fear of contracting the disease. Tens of thousands of jobs were lost, and Detroit, which is 80% Black and has a high level of poverty, has been especially hard-hit by the virus and economic woes.
Schools were closed for months, then reopened and shuttered again this month in Detroit after the virus surged again. In-person classes may have to be scratched for the remainder of the school year in the city.
"Frankly, we have a lot of folks in the community that are just done with the pandemic," said Bozyk. "It's hard to be in social isolation for 13 months. Nobody wants that. That's not good for the psychological health. But as a medical practitioner treating covid, I wanted to make covid go away. I would tell everyone to stay home until we get herd immunity."
Officials hope that the latest surge has started to recede. There were more than 400 covid-19 patients Thursday morning at six Henry Ford Health System hospitals in the Detroit area, down 10% from earlier in the week.
As Michigan has struggled to control another surge, the national outlook has improved. Cases nationwide have drastically decreased since a peak in January, and there are fewer than half as many people hospitalized.
More than 50,000 new U.S. cases were reported Saturday, and case rates are similar to those of the second wave last summer, though they have fallen significantly from the third wave over the winter. But the average number of vaccine doses being administered each day, which rose for months and peaked at 3.38 million, has now dropped to 2.86 million, its lowest level since March 31, according to data from the CDC.
The vaccination rate stopped climbing on April 13, when federal health officials recommended pausing the use of Johnson & Johnson's vaccine to allow researchers to examine a rare blood-clotting disorder that emerged in six recipients. The Food and Drug Administration lifted the pause Friday, opting to add to vaccine labeling a warning about the risk.
Experts aren't sure why daily vaccinations have begun falling, or whether vaccine hesitancy, an issue before the Johnson & Johnson pause, is entirely to blame. They suggest the issue is more complicated. Many Americans who were eager and able to be vaccinated have now been inoculated, experts believe, and among the unvaccinated, some are totally opposed while others would get a vaccine if it were more accessible to them.
Whatever the reason for the slowdown in vaccinations, it could delay the arrival of herd immunity, the point at which the coronavirus cannot spread easily because it cannot find enough vulnerable people to infect. The longer that takes, the more time there is for dangerous variants to arise and possibly evade vaccines.
White House and state health officials are calling the next phase of the vaccination campaign "the ground game," and they are likening it to a get-out-the-vote effort.
"We're entering a new phase" in the country's vaccination effort, said Dr. Mark McClellan, former commissioner of the FDA and director of the Duke-Margolis Center for Health Policy at Duke University.
"Now, it's more about bringing vaccines to the people who want them but haven't been able to easily reach the existing sites," McClellan said.
Information for this article was contributed by Corey Williams, David Eggert, Lindsey Tanner and Ed White of The Associated Press; and by Mitch Smith, Sarah Mervosh, Isabella Grullon Paz, Andrea Kannapell and Bryan Pietsch of The New York Times.