More than 38 million people worldwide have been infected with the coronavirus, and as of Monday, fewer than five of those cases have been confirmed by scientists to be reinfections.
Nevertheless, fears of repeat bouts of illness, impotent vaccines and unrelenting lockdowns were raised anew when a case study about a 25-year-old man in Nevada was published on Monday. The man, who was not named, became sicker the second time that he was infected with the virus, a pattern the immune system is supposed to prevent.
And rare as these cases may be, they do indicate that reinfection is possible, said Akiko Iwasaki, an immunologist at Yale University, who wrote a commentary accompanying the Nevada case study, published in The Lancet Infectious Diseases.
The New York Times asked more experts what is known about reinfections with the coronavirus.
It’s impossible to know how widespread the phenomenon is, they told us. To confirm a case, scientists must look for significant differences in the genes of the two coronaviruses causing both illnesses. In the U.S., many people were not tested unless they were sick enough to be hospitalized. Even then, their samples were usually not preserved for genetic analysis, making it impossible to confirm suspected reinfections.
Plus, a resurgence of symptoms doesn’t prove reinfection. More likely, these are people experiencing symptoms connected to the original infection.
But people with a second bout may pass the virus to others. An infection in a patient in Hong Kong was discovered only because of routine screening at the airport, and the man was isolated in a hospital even though he had no symptoms. But his viral load was high enough that he could have passed the virus to others.

Uncontrolled coronavirus outbreaks in the U.S. Midwest and Mountain West have strained hospitals, pushed the country’s case curve to its highest level since August and heightened fears about what the winter might bring.
Sixteen states each added more new cases in the seven-day period ending Monday than they had in any other weeklong stretch of the pandemic. North Dakota and South Dakota are reporting more new cases per person than any state has previously. And in Wisconsin, home to 10 of the country’s 20 metro areas with the highest rates of recent cases, crews are preparing a field hospital at the state fairgrounds.
“While we are hopeful we can flatten the curve enough to never have to use the facility, Wisconsinites across our state are struggling and they are rightfully scared of this virus,” Gov. Tony Evers wrote to legislative leaders this week in a letter seeking support for his mask order and limits on public gatherings.
About 50,000 new cases are being reported each day on average in the United States for the week ending Monday. That is still far less than in late July, when the country averaged more than 66,000 daily cases.
But the country’s trajectory is worrisome — and worsening. Many experts fear what could happen as cold weather encroaches on more of the country and drives people indoors, where the virus can spread more easily.
New cases are trending upward in 36 states, including much of the Northeast, which is starting to backslide after months of progress, and in Illinois, which surpassed 9,000 total deaths this month.
More than 820 new deaths and more than 54,500 new cases were announced across the country on Tuesday. Idaho and Wisconsin set single-day records for new cases.
Hospital beds are filling with virus patients, especially in the Northern Plains states, according to data compiled by the Covid Tracking Project. Its data shows that 36,034 people are currently hospitalized with Covid-19, a higher number than at any time since Aug. 29. Testing remains insufficient in much of the country.
“After nine months of battling this virus and hearing the updates each day, many of us forget that the hospitalizations and deaths are more than just numbers,” Dr. Ngozi Ezike, the director of the Illinois Department of Public Health, said on Tuesday. “They are our family, friends, and loved ones who have been directly impacted by Covid-19, which continues to spread.”

Northern Ireland will begin a four-week lockdown with schools closing for two weeks, the government announced on Wednesday, in an effort to stamp out a surge in coronavirus cases that have risen to their highest level.
Arlene Foster, Northern Ireland’s first minister, announced the new measures in the regional legislature, known as Stormont, noting a “very worrying increase” in the number of new coronavirus cases. While localized restrictions have been in place for some time, cases have continued to surge, and public health experts warn that if they continue at their current pace, hospitals could soon become overwhelmed.
“This is deeply troubling and more steps are urgently needed,” Ms. Foster said.
Under the tightened restrictions, which will begin rolling out on Friday, pubs and restaurants in Northern Ireland will close for the full month, and only those that provide take out or delivery services will be allowed to open. Schools had already been scheduled to close for a week as part of a fall break, and that time off will now be doubled. Retail shops, however, will be allowed to remain open. The government has shied away from labeling it a so-called “circuit breaker” lockdown as it doesn’t reach the full level as the initial lockdown in the spring.
Northern Ireland, with a population of about 1.8 million people, is reporting an average of nearly 900 new daily cases this week, compared with an average of just over 100 during the height of the first wave of the pandemic in mid April, according to figures compiled by the Belfast Telegraph.
Of the region’s nearly 22,000 total recorded cases, more than a quarter have occurred in the past seven days. Ms. Foster said the new measures would allow the region to put a halt on current widespread transmission of the virus, but noted that the process of fighting the pandemic would be a long-term one.
“We will need to exit these arrangements most carefully,” she said. “We must reach a different place on both the numbers and getting back to the basics of social distancing.”

England began its new three-tier system for its coronavirus response on Wednesday, with the Liverpool region entering the “very high” alert level. New restrictions in the city, in England’s northwest, include a ban on meeting those from different households indoors and the closure of pubs and bars.
As bars closed at 10 p.m. on Tuesday, the last hurrah before the new measures, patrons poured out onto the street in Liverpool’s Concert Square. Videos posted to social media showed crowds of mostly young people packed together, embracing and dancing in the street, even as area hospitals have braced in recent days for a new wave of coronavirus admissions. The police dispersed the crowd as the scene grew increasingly chaotic, and videos showed a group rushing a police car.
Liverpool’s five members of Parliament have been highly critical of the government’s decision to impose new restrictions on their region, warning in an open letter that the measures mean Liverpool “risks being dragged back to the 1980s” without financial support and called for a broader national lockdown.
The measures come as Prime Minister Boris Johnson of Britain faces criticism for ignoring scientific advice for a brief nationwide lockdown — saying it would come at too high a cost — and instead implementing the new three-tier system.

For some companies, the only response to the pandemic has been to hunker down and try to avoid running out of cash before their customers can return.
Pret, the 37-year-old British sandwich and coffee chain that’s ubiquitous in central London, is now clearly willing to try anything:
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Pret wants to sell its food in supermarkets, and has already begun selling coffee beans on Amazon.
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It has signed up to all the major food delivery platforms to bring its sandwiches, soups and salads to its work-from-home customers.
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It opened a so-called dark kitchen in North London to prepare its food strictly for delivery, modeled on the success of Sweetgreen and Shake Shack, and hopes to open another dark kitchen in either New York or New Jersey soon.
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It is devising a special menu of hot evening meals for delivery, such as a Chipotle Chicken Burrito Bowl.
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And then there is the coffee subscription, an effort to drive people back to the stores: Five drinks a day made by a barista (coffees, teas and smoothies) for 20 pounds ($26) a month. On the face of it, it could be an extraordinarily good deal. With two lattes a week, a subscriber will break even. And the first month is free. (Small print: You can’t order five drinks at once — there must be 30 minutes between each drink order.)

From rural India, he worshiped President Trump like a god, praying to a life-size statue of the American leader in his backyard every morning.
Bussa Krishna, a widowed farmer in his 30s, became a fan about four years ago, when the president appeared to him in a dream to predict that India’s national cricket squad would beat its archrival, Pakistan, in a cricket match.
India won, “and from that day he started worshiping Donald Trump,” said Vivek Bukka, one of his cousins.
The young farmer was also drawn to Mr. Trump’s “straightforward ways and blunt speech,” said Vemula Venkat Goud, the headman of Mr. Krishna’s village in the southern state of Telangana.
As Mr. Krishna’s devotion to Mr. Trump intensified, he commissioned the construction of a shrine in his backyard with the life-size statue, Mr. Vivek said. He worshiped it for an hour or two each morning, as one might when praying to gods in the Hindu pantheon.
When Mr. Trump announced that he had tested positive for the coronavirus, Mr. Krishna was devastated.
“I feel very sad that my god, Trump, has contracted the coronavirus,” he said in a tearful video on Facebook. “I ask everyone to pray for his speedy recovery.”
He stopped eating to show solidarity with the president, his family said, and fell into a deep depression. On Sunday, he died of cardiac arrest. There is no evidence linking his death to his fasting.