ALBANY — For months, as they planned for a possible resurgence of the coronavirus, New York’s leaders talked about how a strict set of scientific metrics would guide decisions about whether to reimpose restrictions and closures that helped tame the virus in the spring.

But as COVID-19 has made its expected comeback, several statistical thresholds that were once supposed to trigger shutdowns have been eased or abandoned.

The latest example came this week, when Gov. Andrew Cuomo made clear he had reversed course on a plan to force schools to switch to remote-learning in regions where 9% or more of the people who seek coronavirus tests are found to have the virus.

Schools can officially stay open in counties that cross that threshold, if they launch testing programs and can show that the virus is spreading at a lower rate among students than in the general population, Cuomo said.

“If their schools are below the level of positivity in the community, then they can keep the schools open,” Cuomo said Monday. “It is up to the local school district to make that decision. My position has always been if the children are safer in this school than they are on the streets of the community, then children should be in school.”

It’s a reversal from July, when the governor’s advisory council of educators, students, parents and leaders of schools and unions set the 9% metric. At the time, Cuomo warned it would not be “intelligent” to keep schools open if they crossed that line.

“We were hoping we would never get to the point where 9% was a factor,” New York State Council of School Superintendent spokesman Bob Lowry said.

Now, seven out of the state’s 10 regions have crossed that threshold since late December, along with over half of the state’s 62 counties.

School leaders are awaiting specifics on Cuomo’s latest announcement, according to Lowry, who questioned whether New York has the capacity to launch new testing programs across the state.

And unions representing teachers and school staff have objected to the change, saying the state is endangering workers by keeping schools open.

“We can’t throw up our hands now — the positivity triggers for closing must be upheld, and if they are exceeded, we must close buildings and then redouble our efforts to crush community spread so they can reopen,” American Federation of Teachers President Randi Weingarten and New York State United Teachers President Andrew Pallotta said in a joint statement.

New York state has averaged around 14,400 new cases of the virus per day over the past seven days, up 22% from the week before.

About 17,000 school-aged children in New York have tested positive for COVID-19 since Dec. 23 alone. And nearly 13,700 on-site teachers have tested positive since Nov. 1, including about 3,000 public school teachers in New York City, according to state figures.

Cuomo has defended changes to the state’s plans by saying knowledge of the virus and how it spreads is constantly evolving.

Last spring, Cuomo set target metrics, based on hospitalizations, percentage of positive tests, contact tracing capacity and other factors, that would dictate when regions of the state could reopen things like schools, restaurants and office buildings.

Regional teams were to monitor the data and either “slow or shut off reopening” if needed.

But as cases began to tick up in September and October, that approach of closing down whole regions was shelved in favor of restrictions on tightly defined “micro-clusters,” some as small as a single neighborhood, identified largely based on test positivity rates.

As cases and hospitalizations surged in November and December, the approach shifted again as big swaths of the state saw their virus numbers surge well past the levels that had once been high enough to land a place in one of the governor’s “red zones” with the toughest restrictions.

By Dec. 11, the governor said he would only impose those zoned restrictions in hot spots where hospitals were running out of beds for COVID-19 patients.

Today, there are no red zones in the state and just eight orange zones — none of which are in Oneida County or Albany County, which have among the state’s highest hospitalization rates. Schools in orange and red zone hot spots — which were originally required to shutter — are now allowed to remain open with testing.

Cuomo has explained the changes by stressing that he’s “following the science” while trying to limit economic disruption in a state weathering a devastating drop in sales tax revenues. He said research suggests schools are no riskier than anywhere else.

“You change strategies as the virus changes, the seasonal changes, the growth pattern changes, and where the growth is occurring,” Cuomo said.

New York City Mayor Bill de Blasio also recently abandoned a metric that he once said was vital to keeping teachers safe.

Over the summer, he had decreed that schools would close when 3% of coronavirus tests in the city came back positive. The Democrat did, in fact, close schools when the city crossed that threshold. But he has since reopened elementary schools to in-person learning, saying new scientific research suggested they weren’t places where the virus spread easily. Middle and high schools remain closed.