The pandemic, paired with natural disasters, drives a record number of illegal U.S. border crossings. - The New York Times

The crossers hailed from around the globe, many of them seeking economic opportunity as the coronavirus pandemic erased hundreds of millions of jobs.

As tens of millions of Americans remain unvaccinated, state and local governments have introduced mandates requiring public employees be fully inoculated against the coronavirus.

The order requires more than 800,000 public workers to be fully inoculated against the coronavirus, save for a religious or medical exemption, or risk losing their jobs.

Widespread public mistrust of the Russian government has translated into skepticism about coronavirus vaccines, experts say, leaving the country vulnerable to a surge in new cases that are now setting records for severity.

medical groups declared a national emergency in child and adolescent mental health triggered by prolonged isolation, uncertainty and grief during the coronavirus pandemic, worsening an existing mental health crisis among children and teens.

WASHINGTON — Federal regulators evaluated for the first time on Friday the safety and efficacy of a coronavirus vaccine for children 5 to 11, saying that the benefits of staving off Covid-19 with the Pfizer-BioNTech vaccine generally outweighed the risks of the most worrisome possible side effects in that age group.

The analysis came on the same day that the Food and Drug Administration posted data from Pfizer showing that the vaccine had a 90.7 percent efficacy rate in preventing symptomatic Covid-19 in a clinical trial of 5- to 11-year-olds.

The agency’s independent vaccine expert committee is set to vote Tuesday on whether to recommend authorization.

As is customary, the regulators took no stance on whether the new use of a vaccine should be authorized.

The first is that Delta has made it very hard to maintain our elimination strategy.

By the end of the day, after an exhaustive question-and-answer session with other health professionals, roughly a third of those present chose to receive a dose then and there.

Having abandoned its highly successful “Covid-zero” elimination strategy in response to an outbreak of the Delta variant, New Zealand is undergoing a difficult transition to trying to keep coronavirus cases as low as possible.

In its ruling, the court’s panel did not condemn the government for forcing people to stay at home to stop the spread of the coronavirus, but the judges struck down the government’s interpretation of its right to decree a state of emergency as well as some specific measures, including stopping people from leaving their official residences to spend the lockdown in a second home.

The Centers for Disease Control and Prevention said on Thursday that Americans could choose a booster dose of a vaccine different from the one they had initially received — the so-called mix-and-match strategy.

Preliminary evidence strongly suggests that mixing two Covid vaccine types produces a stronger immune response than matching the booster to the initial vaccine.

Booster doses of an mRNA vaccine (Pfizer-BioNTech or Moderna) seem to raise antibody levels higher than a booster dose of the Johnson & Johnson vaccine.

Among Americans initially immunized with an mRNA vaccine, the following groups should receive a single booster dose six months or more after their second dose, the C.D.C.

And recipients of the Johnson & Johnson vaccine should receive a booster shot at least two months after the first dose.

People who have received two mRNA vaccine doses or a single Johnson & Johnson dose should still consider themselves fully vaccinated.

Scientists from the Centers for Disease Control and Prevention on Friday took aim at the question of whether the Delta variant of the coronavirus causes more severe disease, finding no significant differences in the course of hospitalized patients’ illnesses during the Delta wave compared to earlier in the pandemic.

But larger and more detailed studies from a number of other countries have found that people with Delta infections were considerably more likely to be hospitalized in the first place — a trend that the C.D.C.

study also said that the proportion of older hospitalized patients needing intensive care or dying had shown some signs of increasing during the Delta wave.

Studies in England, Scotland, Canada and Singapore suggested that the Delta variant was associated with more severe illness, a finding that scientists have said raises the risk that outbreaks of the variant in unvaccinated areas may put a bigger burden on health systems.

study, those studies drew on genomic sequencing, allowing researchers to distinguish infections with the Delta variant and to track patients from before they enter a hospital.

The study, released on Friday, examined roughly 7,600 Covid hospitalizations, comparing July and August — when Delta dominated — to earlier months this year, and found no significant change in hospitalized patients’ outcomes.

The study said that the proportion of hospitalized patients aged 50 and older who died or were admitted to intensive care “generally trended upward in the Delta period,” though the differences were not statistically significant and further work was needed.

studies using similar methods that showed no significant differences in the outcomes of younger people hospitalized before and during the Delta surge.

David Fisman, an epidemiologist at the University of Toronto, ran a larger study that found that people infected with the Delta variant had roughly twice the risk of hospitalization as people infected with variants that had not been labeled a concern.

Fisman’s study, drawing on 200,000 cases and published this month, also showed significantly increased risks of intensive care admission and death among those infected with the Delta variant, after accounting for their age, sex, vaccination status and other factors.

Roughly 70 percent of people with Delta infections in the study were unvaccinated, and 28 percent were partially vaccinated.

Similarly, a study in Scotland from June based on 20,000 Covid cases showed that Delta infections were associated with an 85 percent higher risk of hospitalization, though it allowed for a wide degree of uncertainty about the precise figure.

And data from England, drawn from 43,000 cases and published in August, found that people infected with the Delta variant were just over twice as likely to be hospitalized as people with the Alpha variant, though the researchers in that study, too, were unsure of the precise figure.

Belarusian authorities on Friday horrified some of the country’s doctors by abolishing mask mandates, less than two weeks after their introduction during the pandemic and a day after the country registered a record number of new coronavirus infections.

Lukashenko had dismissed concern over the coronavirus as “psychosis” and refused to impose any restrictions.

“Belarus faces the worst wave of the coronavirus, and it’s not ready for that.”