Gov. Greg Abbott of Texas Tests Positive

Gov. Greg Abbott of Texas tested positive for the coronavirus on Tuesday and is receiving an antibody treatment, though he has no symptoms, the governor’s office announced.

An ardent opponent of mask and vaccine mandates, Mr. Abbott, a Republican, has taken his opposition to such requirements all the way to the State Supreme Court. Mr. Abbott, who is fully vaccinated, will now be isolated in the Governor’s Mansion while receiving monoclonal antibody treatment, which can help patients who are at risk of getting very sick.

“The governor has been testing daily, and today was the first positive test result,” the statement said. “Governor Abbott is in constant communication with his staff, agency heads, and government.”

The announcement came less than a day after Mr. Abbott appeared at a crowded indoor political event hosted by a Republican club in Collin County, a hotly contested area of the fast-growing suburbs north of Dallas.

In the images and in videos posted by the governor’s campaign, Mr. Abbott could be seen smiling and shaking hands with supporters who were largely unmasked. “Collin County is fired up to keep Texas RED,” the governor’s campaign posted.

According to the The Houston Chronicle, Mr. Abbott told those gathered that masks were optional — a stance that he has taken across Texas even as cases have risen sharply and some hospitals are filling to at or near capacity. The governor’s office did not respond to questions about the event.

At least 10 other sitting governors — four Democrats and six Republicans — have contracted the virus since the pandemic began, according to reports compiled by Ballotpedia, a political information site. So have four lieutenant governors, all Republicans.

Vaccination rates in Texas lag those of many other U.S. states, and deaths are rising, though far more slowly than in prior waves, given that a majority of the state’s oldest and most vulnerable residents are now vaccinated. The state has averaged more than 15,000 new cases a day as of Tuesday, up from an average of more than 10,000 cases a day two weeks earlier, according to a New York Times database.

Mr. Abbott, 63, has faced criticism as available intensive-care beds have dwindled in Austin and in other cities. But he maintained his ban on mask mandates, which prohibits local officials from imposing restrictions in their communities.

Fear and frustration over the course of the pandemic in Texas, the nation’s second-most populous state, come as schools were preparing to reopen, raising worries about further spread of the virus.

Last month, the Centers for Disease Control and Prevention issued new guidance recommending that even fully vaccinated people should wear a mask indoors in high-risk areas and that everyone should wear one in schools, regardless of vaccination status. Mr. Abbott, though, doubled down in the opposite direction. He issued an executive order that stopped local governments and state agencies from mandating vaccines and reaffirmed decisions to prohibit officials from requiring that students wear masks.

Across the United States, most counties are experiencing either “substantial” or “high” transmission, according to the C.D.C.

Last week, after Mr. Abbott’s ban suffered at least three legal setbacks, the state attorney general, Ken Paxton, said that he was taking the issue to the State Supreme Court. The setbacks were in areas with Democratic leaders, rampant cases and rising hospitalizations.

The State Supreme Court sided with the state on Sunday, ruling that schools could not make masks mandatory.

Since Americans first began rolling up their sleeves for coronavirus vaccines, health officials have said that those who are immunized are very unlikely to become infected, or to suffer serious illness or death. But preliminary data from seven states hint that the arrival of the Delta variant in July may have altered the calculus.

Breakthrough infections in vaccinated people accounted for at least one in five newly diagnosed cases in six of those states and higher percentages of total hospitalizations and deaths than had been previously observed in all of them, according to figures gathered by The New York Times.

The absolute numbers remain very low, however, and there is little doubt that the vaccines remain powerfully protective. This continues to be “a pandemic of the unvaccinated,” as federal health officials have often said.

Still, the trend marks a change in how vaccinated Americans might regard their risks.

“Remember when the early vaccine studies came out, it was like nobody gets hospitalized, nobody dies,” said Dr. Robert Wachter, chairman of the department of medicine at the University of California, San Francisco. “That clearly is not true.”

The figures lend support to the view, widely held by officials in the Biden administration, that some Americans may benefit from booster shots in the coming months. Federal officials plan to authorize additional shots as early as mid-September, although it is not clear who will receive them.

“If the chances of a breakthrough infection have gone up considerably, and I think the evidence is clear that they have, and the level of protection against severe illness is no longer as robust as it was, I think the case for boosters goes up pretty quickly,” Dr. Wachter said.

The seven states — California, Colorado, Massachusetts, Oregon, Utah, Vermont and Virginia — were examined because they are keeping the most detailed data. It is not certain that the trends in those states hold throughout the United States.

In any event, scientists have always expected that as the population of vaccinated people grows, they will be represented more frequently in tallies of the severely ill and dead.

“We don’t want to dilute the message that the vaccine is tremendously successful and protective, more so than we ever hoped initially,” said Dr. Scott Dryden-Peterson, an infectious disease physician and epidemiologist at Brigham & Women’s Hospital in Boston.

“The fact that we’re seeing breakthrough cases and breakthrough hospitalizations and deaths doesn’t diminish that it still saves many people’s lives.”

The C.D.C. declined to comment on the states’ numbers. The agency is expected to discuss breakthrough infections, hospitalizations and vaccine efficacy at a news briefing on Wednesday.

Most analyses of breakthrough infections have included figures collected through the end of June. Based on the cumulative figures, the C.D.C. and public health experts had concluded that breakthrough infections were extremely rare, and that vaccinated people were highly unlikely to become severely ill.

The states’ data do affirm that vaccinated people are far less likely to become severely ill or to die from Covid-19.

More than five million Americans could be eligible for booster shots of Covid-19 vaccine by late September under a Biden administration plan to combat the Delta variant by giving extra doses eight months after initial vaccinations.

Officials are expected to announce the strategy at a White House briefing on Wednesday. Nursing home residents, health care workers and emergency workers would probably be first in line. Other older people would be next, followed by the rest of the general population.

But the plan depends on several crucial steps taking place in the next few weeks. Most important, the Food and Drug Administration would need to decide that third shots are safe and effective for Pfizer-BioNTech and Moderna, the two vaccines that were rolled out first and have been most used.

Pfizer is farther along in submitting data to the F.D.A. that it says supports the use of boosters. Moderna and the National Institutes of Health are still studying whether a half-dose or a full dose would work better for a third shot, but they expect results soon. Moderna’s chief executive, Stéphane Bancel, has said the firm plans to submit its data to the F.D.A. next month.

Officials envision giving people the same vaccine they originally received, using pharmacies as key distribution points.

Administration officials are discouraging people from seeking booster doses on their own, noting that the F.D.A. has yet to rule on their safety and efficacy. Nonetheless, the C.D.C. says that more than a million Americans have already obtained them, apparently by pretending they were unvaccinated. The officials hope to roll out extra shots in an orderly way, so that people get a booster shot when it is recommended, not simply based on their own fears.

Dr. Danny Avula, the vaccine coordinator for the state of Virginia, said that his state had thousands of vaccine providers already in place and could most likely manage boosters without much change. “What caused so much of the urgency and frenzy of January through April was the limitations in supply,” he said.

The government has more than 100 million doses stockpiled that could be used for boosters, along with tens of millions more doses that have already been delivered to pharmacies and other locations. Even more supply is scheduled for delivery this fall.

In interviews on Tuesday, hospital officials and doctors were supportive of the push for booster shots.

“I think we’re running out of second chances,” said Dr. Matthew Harris, the medical director of the coronavirus vaccination program at Northwell Health, New York’s largest hospital system. “What keeps me up at night is the inevitability of a variant that is not responsive to the vaccine, so if this is how we stay ahead of it, I fully support it.”

Federal officials envision offering additional shots to recipients of the single-dose Johnson & Johnson vaccine, as well as those who got Moderna or Pfizer. But the government began offering the Johnson & Johnson vaccine in March, months later than the others, and only 14 million people have gotten it. By comparison, 155 million people have been fully vaccinated with either Pfizer or Moderna.

Data from a Johnson & Johnson clinical trial in which participants were given two doses is likely to be submitted to the F.D.A. later this month and will guide the government’s recommendation on that vaccine.

At Wednesday’s briefing, administration officials plan to make the case that a booster strategy is essential, even if it must be amended as more data comes in. They are expected to present data showing that vaccine efficacy is declining even though unvaccinated people still make up the vast majority of those who become seriously ill or are hospitalized.

Global Roundup

Getting vaccinated against Covid-19 is “an act of love,” Pope Francis says in a public service ad started circulating online and on television on Wednesday.

The ad shows the pope, speaking in Spanish with English subtitles, with church officials from Brazil, Mexico, the United States and other countries describing vaccination as a moral responsibility.

“Thanks to God’s grace and to the work of many, we now have vaccines to protect us from Covid-19,” the pope says in the ad, which was produced with the Ad Council, an American nonprofit.

In centers of faith, efforts to counter vaccine hesitancy have often been fraught.

Many religious Americans who are hesitant have told researchers that faith-based arguments could persuade them to get the shot.

Pastors in Black communities, where congregants skeptical of the Covid-19 vaccines cite a history of medical mistreatment, have publicly rolled up their sleeves to get inoculated. Orthodox Jewish rabbis have taken to YouTube and Zoom to endorse vaccination. During the Islamic holy month of Ramadan, Muslim groups issued statements emphasizing that the shots were halal, or permissible to use.

Still, the message from some religious leaders has struggled to counter vaccine misinformation. On WhatsApp, recordings of rabbis making unproven claims about the vaccines’ effects on fertility have circulated among Orthodox Jewish communities. And on Instagram, TikTok and YouTube, some churches and Christian influencers have spread conspiracy theories linking vaccines to microchips or blaming those who get a shot for not trusting God’s will.

In other news around the world:

• Japan announced late Tuesday that it was extending a state of emergency in Tokyo and Osaka and expanding it to seven additional prefectures as the country struggles to bring under control its worst outbreak of the pandemic. Nearly 20,000 new cases and 47 deaths were documented in Japan on Tuesday, with Osaka hitting a daily record of 1,856 cases and Tokyo reporting 4,377. The extension of the state of emergency in the capital, which had been scheduled to end on Aug. 31, means that the entire Paralympics, which start on Tuesday, will be held under the emergency declaration.

The summer is supposed to be the quietest part of the school year. But not this time.

As summer fades into fall, many of the major issues dividing the country — masks, transgender rights, critical race theory — have dropped like an anvil on U.S. schools.

Schools were already facing a crisis of historic proportions. They must reopen just as a highly contagious Delta variant of the coronavirus is tearing through communities.

And for many of the country’s 56 million schoolchildren, it has been a year of lost learning and widening inequities.

But at this critical moment, many school officials find themselves engulfed in highly partisan battles. The tense environment comes amid a growing movement to recall school board officials, over everything from teachings on race to school closures. Nationwide, there have been at least 58 recall efforts targeting more than 140 officials so far this year, more than the previous two years combined, according to Ballotpedia.

As a superintendent in Albany, Ore., Melissa Goff first noticed pushback when her district closed classrooms during the pandemic, and a slate of candidates ran for school board largely on a platform to open schools.

But by the time students returned this spring, a new flash point had emerged: Should police officers welcome students back to campus? Though it was a local tradition, some parents said that their children, sensitive after a year of Black Lives Matter protests, felt afraid.

Then, in May, Ms. Goff said, she came under fire for a plan to hold vaccine clinics at local high schools. Though she said the clinics were intended to reach families without much access to health care, Ms. Goff said that some people had seen the effort as “making kids get vaccines.”

As the highly contagious Delta variant fuels a rise in cases around the United States, more indoor mask mandates are returning or being extended: for Chicagoans, New Mexicans and, now until next year, anyone in the country using public transportation or visiting an airport.

Chicago and New Mexico’s mandates, which apply regardless of vaccination status, begin on Friday.

The new rules, announced on Tuesday, come after the Centers for Disease Control and Prevention recommended last month that everyone in communities with growing caseloads wear masks indoors regardless of vaccination status.

Officials said the mask requirements were needed to help stop the spread of the virus. Over the past week, the United States has been reporting about 139,800 new coronavirus cases each day on average, an increase of 52 percent from two weeks ago. The number of new deaths reported is up 87 percent, to an average of 696 deaths per day.

Hawaii, Louisiana, Oregon and Puerto Rico have also implemented indoor mask mandates, as have San Francisco and Washington, D.C.

Though cases have risen eightfold in Cook County, which includes Chicago, since early July, the outlook remains far better than in much of the rest of the country. On a per-capita basis, Cook County is averaging fewer than half as many new cases as the country as a whole. An average of 17 cases per 100,000 residents is emerging each day in Cook County, compared to 43 cases per 100,000 people nationally and 138 cases per 100,000 people in Florida.

Chicago’s new mask mandate extends to bars and restaurants, clubs and common areas of residential buildings, according to the department of health.

Dr. Allison Arwady, Chicago’s health commissioner, said, “I don’t expect that this will be an indefinite, forever mask requirement.”

In New Mexico, Gov. Michelle Lujan Grisham said on Tuesday that masks would be required in all public indoor places starting on Friday and continuing until at least Sept. 15.

New Mexico had previously dropped its mask mandate for people who were fully vaccinated, the Las Cruces Sun-News reported.

“This surge is a terrifying indicator of moving absolutely in the wrong direction,” Ms. Lujan Grisham said at a news conference. “We’re in a terrible place for health care services and for protecting our health care workers.”

Ms. Lujan Grisham also announced that teachers and all workers at public, private and charter schools in the state would have to be vaccinated or face regular testing. That mandate goes into effect on Monday.

The Transportation Security Administration said on Tuesday that it was extending its mask mandate for airports, airplanes and public transportation in the United States through Jan. 18, 2022. Travelers under the age of 2 and those with certain disabilities are exempt, Sari Koshetz, a spokeswoman for the agency, said.

Requiring masks has become a hot-button political issue, and Republican governors like Ron DeSantis of Florida and Greg Abbott of Texas have banned local governments and school districts in their states from imposing mask mandates.

That has not stopped districts in those states from trying, and legal battles about the requirements are still playing out.