Scientists say they are seeing signs of lasting immunity to the coronavirus, even in those who only experience mild symptoms of COVID-19.

A slew of studies show that disease-fighting antibodies, as well as B-cells and T-cells that can recognize the virus, appear to persist months after infections have run their course, The New York Times reported.

“This is exactly what you would hope for. All the pieces are there to have a totally protective immune response,” said Marion Pepper, an immunologist at the University of Washington and an author of one of the new studies, which is now undergoing review by the journal Nature.

“This is very promising,” said Smita Iyer, an immunologist at the University of California, Davis, who is studying immune responses to the coronavirus in rhesus macaques, told the Times. “This calls for some optimism about herd immunity, and potentially a vaccine.”

Although researchers cannot predict how long these immune responses will last, experts consider the data to be the first proof that the body has a good chance of fending off the coronavirus if exposed to it again.

“Things are really working as they’re supposed to,” Deepta Bhattacharya, an immunologist at the University of Arizona, told the Times. Bhattacharya is an author on one of the new studies, which was published on medRxiv, a pre-print server for health research that has not yet been peer-reviewed.

While scientists race to find a way to reach herd immunity against the coronavirus, the second largest school district in the nation has announced an ambitious COVID-19 testing program. Los Angeles Unified said it plans to periodically test nearly 700,000 students and 75,000 employees to try to determine when in-person instruction can resume safely, the Washington Post reported.

The district was one of the first in the country to announce that students would not be returning to classrooms in the fall. Working with the University of California at Los Angeles, Johns Hopkins University, Stanford University, Microsoft and major health insurers, the district will now build its own testing and contact-tracing system for a school population that is larger than many American cities, the Post reported.

Teachers who are working from school buildings will be the first to take part in the program. Tests will then be given to all other staff members and students to establish a baseline, the newspaper reported. The district also plans to offer testing to any relatives of students or staff who show coronavirus symptoms.

As schools reopen, COVID cases among kids on the rise

With millions of American children returning to school this month, a new study shows that at least 97,000 kids were infected with COVID-19 during the last two weeks of July.

According to the report from the American Academy of Pediatrics and the Children’s Hospital Association, at least 338,000 U.S. children had tested positive through July 30, the Times reported. That means that more than a quarter of those cases had come up positive in the second half of July alone.

Already, some schools have tried to reopen and then had to order quarantines or close after COVID-19 cases were reported among students and staff, the Times reported.

In the new report, states in the South and West accounted for more than 7 of 10 infections. The count could be higher because the report did not include complete data from Texas and parts of New York State outside of New York City.

There were differences in how states classified children: Most places cited in the report considered children to be no older than 17 or 19. But in Alabama, the age limit was 24, while it was only 14 in Florida and Utah, the Times reported.

Though public health officials say that most children do not get severe illness, a new report from the U.S. Centers for Disease Control and Prevention found that a new, more dangerous COVID-19 condition known as Multisystem Inflammatory Syndrome in Children has struck children of color far more often than whites.

From early March through late July, the CDC received reports of 570 young people — ranging from infants to age 20 with the condition, the Times reported. Of those, 40 percent were Hispanic or Latino, 33 percent were Black and 13 percent were white. Ten died and nearly two-thirds were admitted to intensive care units, the report found.

By Monday, the U.S. coronavirus case count surpassed 5.4 million as the death toll neared 170,000, according to a Times tally.

According to the same tally, the top five states in coronavirus cases as of Monday were: California with over 628,500; Florida with more than 573,000; Texas with almost 570,000; New York with over 430,000; and Georgia with over 220,000.

Nations grapple with pandemic

Elsewhere in the world, the situation remains challenging.

India has passed Britain to have the fourth-highest death toll in the world from the coronavirus, after the United States, Brazil and Mexico, the Post reported.

By Monday, India had more than 2.6 million confirmed cases of the infection and nearly 51,000 deaths, a John Hopkins tally shows. Britain remains the worst-hit country in Europe, the Post reported.

Brazil is also a hotspot in the coronavirus pandemic, with over 3.3 million confirmed infections by Monday, according to the Hopkins tally. It has the second-highest number of cases, behind only the United States.

Cases are also spiking in Russia: As of Monday, that country reported the world’s fourth-highest number of COVID-19 cases, at over 925,500, the Hopkins tally showed.

Even New Zealand, a country that hadn’t seen a new coronavirus case is 100 days, hasn’t been spared.

On Monday, New Zealand Prime Minister Jacinda Ardern said the country’s general election, scheduled for Sept. 19, would be pushed back a month, the Post reported. The move comes as New Zealand grapples with a new wave of COVID-19 infections that have prompted a return to lockdown restrictions in parts of the country.

Worldwide, the number of reported infections passed 21.7 million on Monday, with nearly 776,000 deaths, according to the Hopkins tally.

More information

The U.S. Centers for Disease Control and Prevention has more on the new coronavirus.