New York City is the only major U.S. school system still considering in-person classes this fall, after Chicago rebuffed President Donald Trump’s calls to reopen to avoid further strain on the U.S. economy.

Chicago Public Schools will begin the academic year with all-virtual learning, the nation’s third-largest district announced Wednesday, after administrators bowed to pressure from nervous staff and parents. New York City officials say they are still on track to open in September with a hybrid of in-class and remote instruction, though they need approval from Gov. Andrew Cuomo, who has said he will make a final decision this week.

The national rush to all-remote learning will keep parents struggling to work and teach their children simultaneously, businesses navigating those conflicts, and the virus-wracked country that much further away from normality.

“It’s a huge blow to the economy, and to the long-term potential for growth,” said Diane Swonk, chief economist at Grant Thornton in Chicago. “Unfortunately we’ve put ourselves in a position where it’s getting harder to see how we’re going to sustain a rebound in the third quarter.”

New York Mayor Bill de Blasio speaks with volunteers in Brooklyn in June. De Blasio says that public schools will shut down if the city’s infection rate exceeds 3 percent over seven days.  Bloomberg/Michael Nagle

In Chicago alone, the decision affects 355,000 students — kids whose parents had expected them to be in classrooms starting Sept. 8. Other major school districts that have already opted for virtual instruction for at least the start of the year include Los Angeles, San Diego, San Francisco, Miami, Atlanta and Houston. If New York City joins in, that would affect the families of another 1.1 million students.

The cities are taking these steps as COVID-19 infections spike across the U.S., choosing to be cautious amid conflicting data about how susceptible kids are to contract or spread the disease.

Coronavirus cases in the U.S. increased 1.1% Wednesday compared to the day before, according to data collected by Johns Hopkins University and Bloomberg News. The virus, which has infected 4.79 million Americans and killed more then 158,000, is surging in many parts of the South and West, as the Midwest and Northeast try to rein in flare-ups.

California reported its second-biggest day of new cases on Wednesday and the positive-test rate in Texas climbed for a fourth-straight day. In New York City, one of the earliest parts of the U.S. to be hit hard, Mayor Bill De Blasio stepped up enforcement of quarantines for out-of-state visitors with checkpoints at airports and train stations.

North Carolina paused its reopening for five weeks, keeping businesses including bars, movie theaters and bowling alleys closed, and limiting the size of gatherings.

“Other states that lifted restrictions quickly have had to go backward as their hospital capacity ran dangerously low and their cases jumped higher,” said Governor Roy Cooper, a Democrat. “We won’t make that mistake in North Carolina.”

The decisions about travel, business and education are being made against unrelenting pressure from Trump, whose theories on the topic aren’t always supported by his own health experts.

“This thing’s going away — it will go away like things go away and my view is that schools should be open,” Trump said Wednesday on Fox News. Children “are virtually immune from this problem. And we have to open our schools.”

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, has rejected this claim. There are parts of the country where schools shouldn’t open to in-person teaching, the doctor told Bloomberg Television on Wednesday, and testing for the disease needs to improve, especially in the speed to obtain results.

There is conflicting data about how COVID-19 is transmitted to and from children,

A study published in JAMA last month — based on work in a Chicago pediatric hospital — suggests infected kids with even just mild symptoms can still have 10 to 100 times the concentration of SARS-CoV-2 in their noses and throats as older kids or adults, making them more likely to spread it. An earlier Chinese study, however, found that most children with COVID-19 admitted to a hospital lived in households with previously infected adults, indicating the child caught the virus from the adult rather than transmitting it.

A small number of kids have died or required intensive care as a result of either the respiratory failure commonly associated with the virus or an inflammatory condition sometimes described as similar to Kawasaki disease that causes heart or circulatory problems.

That leaves school officials largely at the mercy of their local health officials for guidance. In Chicago, the district will work with the city Department of Public Health to assess if it is safe to open with hybrid learning in the second quarter on Nov. 9.

The economic effects of keeping children out of school go beyond matters of convenience and pocketbook. They also expose imbalances in the economy, with some children unable to access the internet as easily as others.

“The first-order short-term economic impacts will be likely centered around what this does to families needing childcare; loss of school meals for the kids making hunger worse; and whatever furloughing the district is doing,” said Diane Schanzenbach, professor at the School of Education and Social Policy at Northwestern University. “Long term, the costs of all of this lost learning will be with us for decades.”

Senate Republicans have proposed a bill that would provide $70 billion to K-12 schools, but that may not be enough to safely reopen, or even to go remote and provide needed tech to low-income families. More than $116 billion will be needed to safely reopen the nation’s public schools, according to an estimate from the American Federation of Teachers union.

The teacher’s unions have been lobbying heavily against in-person school, citing budget restraints and health risks for staff and pupils. In Chicago, educators already went on strike last year to demand more nurses, librarians and counselors. The Chicago Teachers Union estimated last month that it would cost between $450 million and $1.7 billion to reopen the city’s public schools safely, depending on the model.

New York City’s hybrid plan, which includes schools getting cleaned daily and mandatory masks, has been criticized by state officials, who have described it as more of an outlier. De Blasio says they will shut down if the city’s infection rate exceeds 3% over seven days.

“We are trying to maximize in-person learning for the good of our kids because we know it makes a world of difference,” de Blasio said during an Aug. 3 news briefing. “Online is a tool we will use when we need to use it, but it’s inherently imperfect.