No one wants to go back to lockdown. Is there a middle ground for containing Covid-19?

First came the freezes.

Governors last month started to “press pause” on the next phases of their reopenings as Covid-19 cases picked back up. Now, in certain hot spots, they are starting to roll back some of the allowances they’d granted: no more elective medical procedures in some Texas counties. Bars, only reopened for a short time, are shuttered again in parts of California. And on Monday, Arizona’s governor ordered a new wave of gym, bar, and movie theater closures for at least the next month.

These are measured retreats — a far cry from the lockdowns that much of the country burrowed into starting in March. But leaders are desperately hoping that the incremental approach can make a dent in the spread of the virus at a time when another round of lockdowns — and their accompanying disruptions to education, the economy, and the public psyche — seems beyond unpalatable, both politically and socially.

They come as Texas, Florida, and other states are seeing record highs in daily coronavirus infections and intensive care units are teetering toward capacity, further proof that the coronavirus will run loose when given the chance. They also raise a serious question: whether such half-measures are sufficiently intensive — and were put in place in time — to have the necessary impact.

“This is a good step to getting a handle on the epidemic,” said Ana Bento, a disease ecologist at Indiana University. “It still might not be enough.”

Even before states began to emerge from their lockdowns, experts were already trying to gauge which cocktail of interventions they could turn to should cases spiral again without having to rely on stay-at-home measures. They hoped more precise interventions — whether focused only on certain communities or business sectors or designed to protect the most vulnerable — could put out flare-ups of cases, a way to balance preventing the spread of Covid-19 from swamping health systems while still sustaining some semblance of society and economic activity.

Now, states are going to find out if more targeted approaches can work. If they don’t, and if people don’t embrace other basic precautions like masking and distancing, it could require governors to reinstate even more restrictions. And if communities can’t contain their outbreaks, what might be left is another stay-at-home period — a sign, experts say, that economies won’t function until local epidemics are mitigated.

“Cutting a middle ground where people don’t change their behavior is probably not tenable,” said Barry Bloom, an infectious disease expert at Harvard’s T.H. Chan School of Public Health. “If people don’t do it voluntarily, then I think you have to start closing things so they don’t have the option of transmitting and being transmitted to.”

The challenge is, it can take some time to know if interventions are working. While new steps to keep people away from each other have an immediate effect on transmission, that won’t show up in case counts for some time, given that it can take a few days for a person to start feeling sick, then a few days more to get tested, then a few more to get results. That means infections that are reported a week and half from now have already occurred. And if the new measures aren’t sufficient to reduce transmission, spread will just continue to grow in the interim — though perhaps at a slower rate.

Public health experts sometimes liken various interventions to slices of Swiss cheese. One slice — say, suspending sporting events — prevents some transmission, but the virus still has lots of holes to pass through, meaning lots of opportunities to transmit. By layering slices — promoting masks, no theater or concerts, limiting group activities, dining only outside — the idea is to stack enough strategies to cover up the holes left by any one slice and to block the amount of virus that can get through.

Lockdowns, then, are like plopping a whole wheel of cheese on the problem. They’ve been shown around the world to dramatically cut rates of transmission, but they also introduce all sorts of economic, social, and health problems that communities want to avoid. Essentially, experts are trying to find the stack of cheese slices that can keep spread from overwhelming hospitals and minimize disease while creating the fewest disruptions to life.

The timing of imposing restrictions also matters greatly. An intervention that could have a big enough impact to bend the curve if instituted on a given day might no longer provide that drag if put into place weeks later. Once the spread balloons past a certain point, there would just be too much virus in the community for halfway measures to succeed.

“I would just urge people to remember if you put in milder interventions earlier on so that you do not build up this big powder keg of infections underneath you, which are then eventually going to start flowing into the ICUs, that’s a better outcome than allowing a large outbreak, which requires a shut down,” said Harvard epidemiologist William Hanage.

If states are being more targeted with their measures, experts are pushing them to be smarter as well. They say governors should be prioritizing which institutions need to be open, and then devising strategies to accomplish that. Schools — which foster not only education and development, but provide child care and, for many, meals — are top of mind. So, experts say, the question shouldn’t be will schools open in the fall, but rather, what can we do so that they can?

“We have this viewpoint that we will just reopen everything and go back to normal, but just do everything a bit more safely,” such as by wearing masks or capping capacity, said Helen Jenkins, an infectious disease epidemiologist at Boston University’s School of Public Health. But if everything that opens again contributes some amount to overall transmission, the approach might have to be keeping things like bars and casinos closed if you really want schools to have a chance this fall, she said.

Schools can open in areas with low levels of transmission, “but if everything reopens, we risk tipping things over the edge to high transmission,” Jenkins said. “And then everything has to close down, and that’s something that no one wants.”

As they try to limit restrictions, officials have zeroed in on a particular type of establishment: bars. There, people crowd together indoors for long periods of time — factors that encourage viral spread. Last month, Idaho health officials identified a cluster of 152 cases that originated from bars and clubs around Boise and shut down all venues in the area. Texas and Florida have similarly reimposed rules on bars.

People in their 20s and 30s are also accounting for greater proportions of new infections in Arizona, Texas, and Florida now than at other times and in other places during the U.S. epidemic, leading to speculation that young people are flouting distancing recommendations and packing unsafely into bars.

The Trump administration has pointed to the cases among young people, who generally experience milder infections, as well as a nationwide daily death count far below its level in April, to say that the country is not in the same crisis it was in months ago. Administration officials have not rolled out new strategies for mitigating the recent spikes in cases in the South and West.

“Younger Americans have been congregating in ways that may have disregarded the guidance that we gave on the federal level,” Vice President Mike Pence said Sunday on “Face the Nation.”

But experts have raised several critiques of the administration’s arguments. Whatever the explanation for the bulk of cases among young people — perhaps it’s changes in testing patterns, perhaps older people are taking precautions to protect themselves — cases building up in a certain population won’t stay in that population. The more virus that’s out there, the likelier it is to reach vulnerable populations, like older residents. Plus, even if younger people are generally less susceptible to severe Covid-19, some will still get seriously ill, require medical care, and die.

As for deaths, clinicians have gotten better at caring for Covid-19 patients over the months, and perhaps the concentration of cases among younger people is leading to better outcomes. But experts also caution that deaths are a lagging indicator; the time from when someone contracts the virus to when their death is recorded can be weeks. With hospitalizations rising in many states, it’s likely that deaths will follow in time.

“There is incredible stress on the system, and it appears that might be getting a whole lot worse over the next few weeks,” said Fred Campbell, an internist at UT Health San Antonio.

The situation in San Antonio, where Mayor Ron Nirenberg said cases are rising in “an exponential surge,” led the city to blast out an alert to residents’ phones over the weekend, urging them to stay home and wear masks on essential trips. It was one example of local officials begging for the public’s help, sometimes asking for more than what a state mandates. In Los Angeles County, Barbara Ferrer, the director of public health, said last week that officials “did not expect the increases to be this steep this quickly” about cases rising after reopening, and directed residents to “wear a face covering and keep your distance.” Utah state epidemiologist Angela Dunn on Friday called for “large-scale behavior change on the part of all Utahns to reverse” the record cases the state was seeing.

States where transmission is relatively low are also looking to what’s occurring elsewhere to guide their reopening decisions. This week, New Jersey Gov. Phil Murphy cited “spikes in other states driven by, in part, the return of indoor dining” to push the return of that off “indefinitely.”

Not every state that reopened early is facing an outbreak on the scale of those in Arizona, Texas, and Florida. Colorado started to peek out from its shelter-in-place restrictions in late April, without a corresponding surge in cases.

It’s hard to pinpoint any one reason that explains the difference. Colorado had an initial wave of cases, so perhaps residents — who, as a whole, are among the country’s healthiest — take more precautions. The state also reopened as case counts were declining, whereas others lifted restrictions as cases were plateauing or even increasing. Its governor, Jared Polis, stressed mask-wearing starting in April.

But cases in recent days have started increasing.

“We are on the razor’s edge,” said epidemiologist Elizabeth Carlton of the Colorado School of Public Health. “We have seen this steady decline in hospitalizations since the beginning of April, and that’s great news. But we are starting to see an uptick in cases.”

Carlton noted that accelerating transmission in Arizona and Utah raises the possibility that cases could spill over into Colorado, where there’s not “some magic wand to protect us.” The reproduction number in the state — the average number of cases that come from each case — is about one, she said, which means that its epidemic, while not worsening, is not improving.

“Equilibrium can be good, but it can also be quite nerve-wracking,” Carlton said. “It doesn’t take much to restart the wildfire.”