It’s the most important question since March 2020: When will the Covid-19 pandemic end?

The omicron variant, as well as other unexpected twists and turns with the coronavirus, have made the question a difficult one to answer. But, since the beginning, so has the lack of consensus on what level of Covid-19 the US and world are willing to tolerate. Even as government officials have ramped up and scaled down restrictions, they’ve seldom given clear standards — goals with specific metrics attached to them — explaining what’s driving the changes. All of that stands to replay with omicron.

“It’s been a major problem,” Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, told me. “If you’re not articulating what the metrics are that are driving your public health decision-making, it makes everything more opaque to the general public.”

The initial objective was to “flatten the curve.” But that was vague: The idea was to keep Covid-19 spread, and ultimately hospitalizations, down to avoid overwhelming the health care system. But there was never a defined standard for how low cases or hospitalizations should be, and what threshold was too high.

Then even that goal seemed to fall by the wayside. Instead, officials across the country seemingly adopted and eased rules based on media attention, political sentiments, and public backlash.

For many people, life might already seem back to normal. Yet there are still some rules in place, including mask mandates in some jurisdictions and many restrictions on schools, with no clear signal on when they will end. And the Covid-19 death toll in the US is still at more than 1,000 a day.

With experts now widely in agreement that “Covid zero” (true elimination of the virus) is impossible, the lack of clear goals is even more jarring: It seems as though the country will have to accept some level of Covid-19 in the foreseeable future, but there’s no clarity on what that means.

How many cases, hospitalizations, or deaths are we willing to tolerate? Or are those even the right metrics? Public officials, at least, aren’t offering clear answers.

“It’s like when you’re a kid and the teacher asks you to show your work,” Adalja said. “Oftentimes, [public officials] didn’t show their work. They just said, ‘This is how it is.’”

Some places have done better. Australia, for one, invoked clear guidelines for its harsh lockdowns throughout the pandemic. As “Covid zero” has become impossible, it has tied its rules to higher vaccination rates and individuals’ vaccination status.

Clear goals, signaling when restrictions would lift, would have the advantage of transparency. They might have bigger benefits as well, like rebuilding much-needed trust in public health officials and communications and motivating the public to better follow the rules. If omicron ends up causing more surges of infections and deaths, and officials respond with new restrictions, providing a light at the end of the tunnel could help show people why such steps are necessary and possibly push more of the population to adhere to the measures.

But for that to be the case, America has to decide on its end goal with Covid-19 — and, so far, it hasn’t. “We haven’t learned,” Adalja said. “The same mistakes are still being made.”

The metrics used matter — and may change over time

The basic idea, experts told me, should be for US leaders to provide clear goals that the public can easily track, and tie all remaining and new Covid-related rules around the new objectives. “If you have a set of policies that restrict people’s behavior, having pretty clear guidelines about when you will pull those back seems like a reasonable thing,” Robert Wachter, chair of the University of California San Francisco Department of Medicine, told me.

Right now, the most logical endpoint is to reduce the number of cases: If the idea is to minimize the spread of Covid-19, then what better way to guarantee that than to ensure actual infections are below a certain threshold? At this point, we have plenty of evidence that case numbers predict the worst outcomes of Covid-19 too, with a clear trend since the start of the pandemic that cases rise, hospitalizations rise roughly two weeks later, and deaths rise roughly two weeks after hospitalizations.

So what’s the right number of cases? This is, admittedly, going to be an arbitrary threshold no matter what. In the past, some organizations, including Vox, have cited four daily new coronavirus cases per 100,000 people as an acceptable standard. But 4.1 daily cases per 100,000 isn’t really all that much better than 3.9 cases per 100,000; four is an arbitrary cutoff. Still, some number has to be set for any of this to work, and it should be low enough to ensure the Covid-19 virus really isn’t spreading too quickly.

It’s also important to make sure a drop below, say, four per 100,000 is sustained. Otherwise, there could be a yo-yo effect in which restrictions abruptly come and go as the number of cases moves a little below and a little above four per 100,000. One way to get around this would be to require that cases stay below the standard for some time — say, two weeks — and don’t rise in that period. (The US is still above this threshold, although underreporting during Thanksgiving has led to data gaps nationwide.)

Over time, cases may come to matter less. With the vaccines, there is a “decoupling” of cases and serious Covid-19 outcomes: The vaccines don’t perfectly and durably protect from infection, with that protection waning over time, but they do appear to sustainably protect at very high rates — 90 percent and higher — from hospitalization and death. So someone might contract Covid-19, registering a case, but be at much lower risk of death than she would have been a year prior.

“We’re not there yet,” Crystal Watson, senior scholar at the Johns Hopkins Center for Health Security, told me. Because of vaccine hesitancy, “we still have significant proportions of the population and pockets of individuals who are still very susceptible and may be susceptible to severe illness.”

But if a decoupling does happen, then the country would likely want to pay less attention to the number of cases and more to hospitalizations.

As with cases, the acceptable level of hospitalizations will be a bit arbitrary. There are also important distinctions: If the goal is to ensure as few people as possible suffer from Covid-19, then a lower threshold may be warranted. If the goal is to ensure the health care system isn’t overwhelmed, the bar could potentially be set higher.

Another potential goal is a higher vaccination rate. There’s no agreement among experts about what the right number is here. And since more vaccination is always better for public health, any threshold is going to be — you’ve heard this before — arbitrary. But 80 or 90 percent vaccination rates in a community, with significant uptake of boosters (particularly in older and immunocompromised populations), is the kind of range experts have generally mentioned in recent weeks.

Yet another possible goal could be the availability of vaccines and other effective treatments.

With vaccines, for example, restrictions could ease once the shots are truly accessible to everyone for two months. At this point, people who choose not to vaccinate themselves or their children are knowingly taking a risk. And while it really would be better for everyone, including the vaccinated, if the unvaccinated got their shots (since the vaccines still appear to reduce transmission), most of the risk will fall on the unvaccinated while the vaccinated will be by and large shielded from the worst of Covid-19.

So continuing to enforce restrictions around Covid-19, the logic goes, is essentially asking vaccinated people to continue to make sacrifices for unvaccinated people even though the unvaccinated have decided to take a risk with their own health. That seems unfair. So once vaccines are truly available to everyone for long enough, it’s time to move on. (Another way to get at this would be to tie restrictions to individuals’ vaccination status, but so far there’s no political appetite for that in the US.)

“This is not a perfect plan,” Lucy McBride, an internist in Washington, DC, who writes a Covid-19 newsletter, told me. But she argued that prolonged restrictions can cause harm too, as the world has seen with learning loss following school closures. “Covid is one very important threat to our health and well-being. But, for children in particular, so is not being in school without masks.”

The one complication, McBride added, is if a variant appears that hits kids harder or can significantly evade immunity. In that case, the overarching goal could have to change to match the reality on the ground.

All of the goals above don’t have to be exclusive. They could be looked at in combination. But, above all, they should be made explicit.

Maybe clear goals would get more people to follow the rules

The biggest benefit to clearer goals would be transparency.

For much of the pandemic, there’s been little clarity on when restrictions come and go, with officials seemingly following vague readings of the news, evidence, and public opinion. This can make the process of reopening and closing, masking and not, and adopting or ditching any other Covid-related measure feel arbitrary. Particularly in conservative circles, it’s led to charges that Democratic leaders are merely trying to assert control over the population and don’t ever intend to ease mandates.

The lack of transparency is one reason, experts say, that public health communication has frequently faltered throughout the pandemic. As Watson put it, “Uncertainty, and constantly changing expectations without providing reasoning, doesn’t inspire confidence. It confuses people.”

Establishing clear guidelines could help alleviate this. If the goal is to get below four daily new cases per 100,000 people for at least two weeks, for example, then it’s not going to feel arbitrary when a given region surpasses that threshold and restrictions are tightened again. Charges that the goal is to merely control the population and not ever ditch restrictions will be less credible by virtue of there being a clear end goal.

With Covid-19, the world has learned things can quickly change, whether as a result of people prematurely shirking precautions or variants coming seemingly out of nowhere. Clearer goals can’t stop variants, but they can at least offer a baseline for when things are truly turning for the worst and action is warranted. That would not only help people understand why precautions are necessary, but it could help ease panic as people have a baseline to work around instead of vague notions that things might be getting bad again.

An extra benefit, experts said, is clearer goals could motivate people to heed precautions. If people have no idea what they’re working toward and it feels as though the pandemic and related restrictions might last forever, they may wonder if putting their normal lives on hold indefinitely is really worth it. But if they know that there is a clear, set light at the end of the tunnel, they may take the precautions more seriously to get to that light more quickly — and therefore get their lives back.

This concept is intuitive. But experts acknowledged that there’s no good research or data showing that it’s true — and Covid-19, after all, has consistently done a good job wrecking intuitive ideas.

“I can’t say that there’s great empirical evidence that works, and I think we’ve sometimes gotten ourselves in trouble playing amateur sociologists,” Wachter said. “I think it’s logical to believe that people will be comforted knowing that there is a potential endgame here and a goal they can aspire to. But whether it motivates individual behavior? I don’t know.”

Still, given that clearer goals would have their own benefit in more transparency, they’re still worth setting. And if they also have the benefit of pushing more people to heed precautions to defeat the virus, that’s a great bonus.

If nothing else, clearer goals could help add some clarity to a pandemic that’s often been confusing. After a year and a half of uncertainty, giving people something more reliable is a worthy goal on its own.

All of a sudden, it seems a lot of people are getting Covid-19 booster shots. The additional doses of Moderna’s and Pfizer/BioNTech’s vaccines have been approved in the US for people 65 and up as well as at-risk populations, such as people with certain health conditions and front-line workers. Everyone who got the Johnson & Johnson vaccine can now get a booster. Meanwhile, Pfizer is asking for approval of booster shots for all Americans who previously got its vaccine.

But underlying the booster mania is a question that many experts say remains unanswered: What exactly is the point of the extra shot?

From an individual perspective, the answer seems straightforward. The boosters appear to reduce the chance of infection and, likely, transmission of the disease, giving the immune system a refresher. So getting a booster could protect you and those around you by making you less likely to get infected in the first place.

But this simple answer invites a new set of questions. If the desired outcome is maximum protection from any kind of Covid-19 infection, does that mean people should get vaccinated every three, six, nine, or 12 months as antibodies continue to fade? Is that even practical? And does society as a whole benefit from vaccinated people getting even more protection, especially if doses could instead inoculate unvaccinated people around the world?

Some experts say there’s not enough clarity around these questions, even as the country embraces a widespread booster strategy. “What is it that you’re trying to achieve?” Céline Gounder, an epidemiologist at New York University who’s advised President Joe Biden, told me. “That needs to be clearly defined.”

But the Biden administration, which has promised and encouraged booster shots for months, is facing an uncomfortable reality: A campaign for boosters might be the best thing they can do at this stage of the pandemic, especially given who’s most likely to heed guidance from federal officials.

Every expert will say that immunizing unvaccinated people is a far more effective means of controlling Covid-19 than giving a booster to those who are vaccinated. But, after the better part of a year, only about 70 percent of US residents 18 and older are fully vaccinated. Roughly one in five adults remain adamant that they will definitely not get vaccinated or will only do so if it’s required. Months into campaigns pushing people to get vaccinated, those who are still unvaccinated just seem very difficult to move to the vaccinated side.

People who have already gotten vaccinated are probably more persuadable; after all, they already got their first shots. For the Biden administration, then, pushing these people to get another shot may be the easiest path to boosting population-level immunity to some extent, even if it would be preferable to get unvaccinated people to get a shot or two instead. It’s a pragmatic call about what can be done now, rather than aiming for the ideal.

Still, it’s clear that there’s a lot of uncertainty about the why, who, and when of booster shots. Even experts who closely follow this topic for a living don’t have all the answers to basic questions, from whether waning immunity is a big problem to what the definition of a “booster shot” is. When I asked Brown University School of Public Health dean Ashish Jha about unanswered questions, he responded, “Well, there’s a lot.”

These unanswered questions make it harder to determine what booster shots are supposed to do — and whether their benefits truly outweigh the costs.

Is waning immunity really a big problem?

The big argument for booster shots is that the protection from vaccines appears to wane to some extent. But even here, there’s a lot we don’t know.

Some evidence suggests that vaccine-induced immunity against any Covid-19 infection, including those that lead to no illness or mild symptoms, does wane. An earlier study from the CDC found that vaccine effectiveness against infection among New York adults fell from 92 percent to 75 percent between May and July. A more recent study in Science, looking at Veterans Health Administration data, found vaccine effectiveness against infections among military veterans declined from 88 percent to 48 percent between February and October.

Vaccines still offer some protection against infection; 75 percent or 48 percent is better than zero percent. Separate studies, from the Netherlands and the UK, have also shown that the vaccines continue to reduce the risk that someone will transmit the virus — not to zero, but by a statistically significant extent.

And vaccine-induced protection against severe disease and death has mostly held up. In the New York study, vaccine effectiveness against hospitalization was more than 93 percent. In the veterans study, vaccine protection against death was 82 percent for veterans younger than 65, and 72 percent for those 65 and older. Other CDC data, going into September, found unvaccinated people are 11.3 times as likely to die from Covid-19 as those who are fully vaccinated.

We actually don’t know how much these numbers are measuring the vaccines’ protections waning versus the delta variant better evading immunity. And there are statistical paradoxes that can further complicate all of this data.

Still, experts say there is good reason to expect that protection against any infection was always going to wane: Antibodies fade over time. That’s normal; it’s just what the immune system does. But if the immune system keeps some defenses around and can kick into gear if an infection does occur, then someone might get sick and maybe even spread the virus but be largely protected from hospitalization and death.

“When people come into the hospital, they’re not in the ICU because they’ve not gotten a third dose,” Paul Offit, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, told me. Typically, “they’re in the ICU because they haven’t gotten any doses.”

Waning immunity against infection may just be part of the new normal. Many experts now believe Covid-19 will become endemic, sticking around in a similar form like, say, cold and flu viruses. But in that scenario, the virus will very likely be defanged by a mix of natural and vaccine-induced immunity, as well as better medications and other treatments.

“I’m still seeing on Twitter the desire for elimination, but it’s not going to happen,” Monica Gandhi, a doctor and an infectious disease expert at UC San Francisco, told me. Still, she argued, “We’re so lucky. We prevented the worst thing that could ever happen, which is to get super sick from a horrible new virus.”

In that view, maybe waning immunity against infection isn’t, in the long run, that big of a deal.

But we aren’t there yet. Much of the population still isn’t vaccinated, and more than 1,200 Americans are still dying of Covid-19 each day. Right now, there’s too much spread and too much death, so we need all the immunity we can get to fight off the virus.

That means booster shots could ultimately be situational. They might make sense, especially for vulnerable people, when outbreaks are bad or likely to get bad in the future (such as in the fall and winter), but we wouldn’t be trapped in a never-ending cycle in which people should get shots every few months for the rest of their lives.

That gets to another question.

Who actually needs booster shots?

There are two groups that experts widely agree benefit from booster shots: the elderly (65 and up) and the immunocompromised.

For older adults, there are two major considerations. One, this group has always been much more likely to die of Covid-19: People 65 and up comprise 75 percent of Covid-19 deaths in the US. Two, older immune systems seem to get less from the vaccines or, at the very least, see protection wane more quickly; as the study of veterans found, vaccine effectiveness against death was about 10 percentage points lower for those 65 and older than those younger than 65.

People who are immunocompromised, meanwhile, may not get much if any benefit from just the two shots of Pfizer/BioNTech’s or Moderna’s vaccine or the one shot of Johnson & Johnson’s. But there’s some evidence an additional shot or more may increase levels of protection.

Beyond those two groups, Gandhi said, “there’s just not great evidence for boosting.”

There’s even a case that no one should get a booster shot as long as so much of the global population is unvaccinated. Supplies — as well as attention and other resources involved in a vaccination campaign — are limited. Every booster shot that goes to a previously vaccinated American could be one that goes to an unvaccinated person in the Global South, particularly in Africa, which currently has vaccination rates below 10 percent. As long as the coronavirus spreads unchecked globally, it’s more likely to transform into a worse variant — one that’s deadlier, more contagious, or evades current immunity.

“It’s not just about morality and ethics,” Gounder said. “We are so losing sight of what is most important here.”

Still, chances are that at least some people will need boosters after global vaccination efforts scale up. And some people are getting boosters regardless in the meantime. For now, there’s consensus that older and immunocompromised groups should be at the front of the line. But for everyone else, there’s a lot more skepticism — out of a concern that the extra doses for vaccinated people just don’t come out on top of a cost-benefit analysis.

Okay, but should you, the reader, get a booster shot? Most experts have told me that if you’re eligible, you should.

For one, it’s better to be safe than sorry with your personal health. And while it might be better for the dose you’re taking to go elsewhere, that shot’s fate is already sealed — it’s already purchased by the federal government for domestic use and allocated to your local pharmacy, doctor’s office, or wherever else you’re going to get a vaccine. This is a problem to be solved upstream by policymakers, not individuals with personal boycotts of booster shots.

But then there’s another problem: the question of when to get a booster.

How often will people need booster shots?

The simple truth: No one knows how often booster shots will be necessary.

“What are the long-term benefits of a booster? How long does it last? Will we need another booster a year from now? Will we need another booster sooner than that?” Jha said. “We don’t know the answers to that.”

The recent evidence suggests vaccine-induced protection against infection starts to wane after a few months. But that’s only after a person has been fully vaccinated for the first time.

There’s some reason to hope that a booster shot could produce a more permanent effect. “There’s some reasons to believe, immunologically, that once you get a booster six months after your second shot, that that should have a lot more durability than the first two shots did,” Jha said. But, right now, we “can’t prove that. We don’t know for sure. We don’t have that long-term data.”

Even if vaccine-induced immunity does wane, there are other considerations. If in six, eight, or 12 months, Covid-19 cases are low, vaccine protection against severe disease and death is holding up, and especially if few people are dying of the virus, maybe using boosters merely to stop the spread of the disease won’t be worth it.

There is a risk to too much boosting: vaccine side effects, including rare but potentially serious conditions like myocarditis (inflammation of the heart muscle). “Every time you boost your immune response, especially with [Moderna and Pfizer’s] mRNA vaccines, you do have a certain percent of people who are going to get myocarditis,” Offit said. Even with conditions, like myocarditis, that are rare, “if there’s not a clear benefit to that booster dose, that serious adverse reaction becomes more important.”

One possible model, as the virus becomes endemic worldwide, is an annual Covid-19 shot, similar to the flu shot. It’s already possible at American pharmacies to get a flu shot and Covid-19 booster simultaneously, so it’s logistically feasible. This would be a way to keep spread low, helping ensure that the virus doesn’t strike back.

This, however, is all speculative. Experts are in agreement on only one thing here: We need more data.

And then there’s one more question about boosters to answer.

Is the Johnson & Johnson vaccine an exception?

This might seem like a much narrower question than the others, but it’s illustrative.

Among the experts I spoke to, every single one said that the Johnson & Johnson vaccine — originally sold as the one-shot vaccine — likely should have been two shots to begin with. In fact, some experts speculated it would have been two shots if this had been a more typical, less rushed vaccine process, in which Johnson & Johnson had years to study and produce the best vaccine regimen possible.

One major tell is that federal officials approved what they called a “booster shot” for all Johnson & Johnson recipients, instead of limiting the extra dose to specific groups, as they did with other vaccines.

In other words, the “booster shot” for Johnson & Johnson recipients may not be a booster shot at all, but more the equivalent of the second shot that one would get with the Pfizer/BioNTech or Moderna vaccine.

It’s an example of how even the definitions of “booster shot” and “fully vaccinated” remain unclear.

It also shows how hectic times have led to on-the-spot calls riddled with uncertainty. Since the beginning of the pandemic, the public, experts, and officials have made the best calls based on limited and sometimes contradicting information. That includes the rollout of the vaccines and now boosters, up to and including the basic structure of the original vaccine regimens.

This is why all the discussion and debate around boosters can seem so complicated and confusing: It really is complicated and confusing, even for the smartest experts out there. When everyone is working with limited data and hasty judgment calls, the answers aren’t going to be as concrete as anyone would like.

Sometimes that might lead people to move to be safe over sorry, approving boosters that may not have all the evidence for them just yet. “One of the challenges with this pandemic, but really any infectious disease, is you’re making decisions for now, but you’re also trying to anticipate things that could happen,” Jen Kates, director of global health and HIV policy at the Kaiser Family Foundation, told me.

On the flip side, it also means that we, collectively, could be — and probably are — making some wrong calls right now.

As Covid-19 has taught everyone by now, proper responses to pandemics require humility and flexibility. We’re going to need extra doses of both as the world figures out what to do about booster shots.

I started reporting this article with a simple question: What would it look like to build a better police department from the ground up?

Police in the US, after all, are more likely to shoot and kill someone than their peers around the developed world, and disproportionately the victims are Black Americans. Meanwhile, serious crimes are often unsolved — with almost half of murders in 2020 going uncleared.

So I asked a dozen experts, focused on criminal justice, what could be done about this to build better police departments. They gave me a lot of different answers, with a consensus on more accountability, a greater focus on crime prevention and more serious offenses over minor ones, and support for non-police efforts to address root causes of crime, among other ideas.

But they consistently gave the same caveat: America’s gun problem. The US has the most civilian-owned firearms in the world, with more than one gun in circulation for every person. A bevy of research has linked greater gun ownership to more deadly violence in the US — and, America, relatedly, has the highest murder rate out of the world’s developed countries.

For police, the huge number of guns in America also means that every single call is treated as if someone involved could be armed — and that an otherwise nonviolent wellness check, mental health call, or traffic stop could turn into a deadly encounter. US law generally allows police to use force because they merely perceive a threat, and the many firearms in civilian hands give police officers a reason to believe they’re in danger.

“It’s Schrödinger’s gun: It’s always there, but it’s not there until you see it,” Michael Sierra-Arévalo, a sociologist at the University of Texas Austin, told me. “That cost is borne by two parties: It’s borne by the public, when police make mistakes, and it’s borne by police themselves, when they’re attacked by firearms.”

Of course, other factors play a role in how US police behave. Racism, at the individual and systemic level, is a real force throughout much of American society. Racial disparities in all aspects of American life, from health to the economy, can translate to higher crime rates in minority communities, where police are subsequently deployed in greater force. And since the 1970s and ’80s, US policymaking has trended toward a “tough on crime” approach that encourages police to act very aggressively.

But guns act as a ratchet in policing. Firearms make every call to the police more risky, but also make officers and the public perceive every situation as inherently more risky. This helps explain not just how cops themselves behave but why police are involved in so many different calls to begin with, from murders to wellness checks. Armed officials ended up in charge of so many areas of society in part because the US has more guns and sees more deadly violence than its peers.

This complicates any effort to reduce the role of the police in American society. One of the more popular proposals today is to get the police out of mental health crises, replacing the cops called about people in crisis with special teams that take a softer, more public health–minded approach.

But the vast number of firearms makes it more likely these calls could escalate, endangering a member of the response team and potentially requiring armed backup. Eugene, Oregon’s vaunted CAHOOTS program, for example, has reportedly diverted 5 to 8 percent of dispatch calls away from the police by deploying unarmed, health-oriented staff to crisis situations. But as the Eugene Police Department explains, sometimes officers have to be deployed along with CAHOOTS, or even beforehand, to secure a possibly dangerous scene.

Reducing the footprint of police isn’t impossible. But the abundance of guns places limits on how far these reforms can go. To put it another way, there’s a choice that America, as a whole, and its leaders have to make: Do something about all of the guns in circulation, or limit the scope of police reform.

Guns complicate any efforts to reform police

The US has more civilian-owned firearms than any country on Earth. There are about 120 guns for every 100 people, according to 2018 data from the Small Arms Survey. Yemen, in second place, has about 53 guns per 100 people. Canada has about 35 per 100, England and Wales — where police are often unarmed — have nearly five per 100, and Japan has fewer than one per 100.

A long line of research has connected more guns to more gun violence, including police shootings. The issue is not that America has more crime or violence than other developed countries, but that guns make it much easier for an event to escalate from a merely criminal offense to a deadly encounter. For police, this reality makes them more guarded, and, potentially, more likely to shoot unnecessarily.

“Police officers are being asked to make these often very subtle decisions in situations in which they legitimately feel their life is really threatened,” Emily Owens, a University of California Irvine economist focused on crime and policing, told me. “The prevalence of firearms in the United States doesn’t help that situation, certainly.”

To be sure, other factors besides guns, from personal views to systemic issues, contribute to those subtle decisions officers make as well. There are reforms that could be tried even within the context of Americans’ massive stockpile of firearms. But guns act as a constant force in the background, drawing boundaries around how far reforms can go and how well they can work.

As one example, the abundance of guns complicates a key concept in many police reform proposals: a higher bar for getting officers involved at all.

American law enforcement respond to a lot of calls that don’t involve violence or even conflict between people. One recent study in Police Quarterly found the top three calls across nine departments were about traffic, public disturbances (like noise violations, graffiti, fireworks, and public urination), or suspicious people and activities; just 7.2 percent were about violence or involved some kind of conflict between different people. The hope is that police, as armed and possibly violent state actors who can escalate a situation themselves, could be removed from the many lower-level calls.

“If police are going to be the armed emergency first responder, what do you want these people with guns to do?” Tracey Meares, the founding director of the Justice Collaboratory at Yale Law School, said. “There are people whose dogs poop in my front yard, and there’s a law against that. Do I think it’s a good idea to call a person with a gun to deal with that? No, I don’t. Just like I don’t think it’s a good idea for a person with a gun to deal with a noise complaint. I can come up with a whole bunch of other examples.”

But the number of guns among the civilian population raises the chances any given call in America will turn into violence, either by a police officer or by a civilian on the scene. In the UK or Japan, anyone responding to a mental health call — police or otherwise — can safely assume a gun won’t be present; in the US, that’s far from a sure bet.

The potential risk of a hypothetical gun is further complicated by the unpredictable nature of policing. Temple University criminologist Jerry Ratcliffe analyzed 911 calls in Philadelphia for a study in Crime Science. He found that calls for one thing can often turn into an entirely different matter — those about crime often turn out to be mental health cases or “sick assists” (such as helping a person who’s physically ill), and wellness checks sometimes turn out to be violent crimes or missing persons situations.

Even if someone thinks that they might be going into a relatively safe call, it could turn out that’s not the case. Add in the risk presented by America’s guns, and you may have a very volatile, potentially dangerous situation. “You don’t know what you’re getting,” Ratcliffe told me. “You don’t know for sure it’s a nonviolent call when you turn up.”

Most police calls are resolved safely without any serious incident. As New York City Police Department analyst John Hall noted, “just one in every 6,959 [traffic] stops results in an assault on an officer … an officer sustaining serious injury or death from a traffic stop is even rarer.” Still, each cop can respond to multiple calls while on duty — and each call carries a roll of the dice that ends in a dangerous encounter. As Hall put it, “Over the course of a career, these stops add up.”

The officers responding to these calls are also planning for the worst, not the ideal. If there’s a decent chance that someone will encounter a gun at a call — especially if something has already happened to a colleague — officers will tend to be more guarded.

This doesn’t excuse criminal acts or horrifying, avoidable mistakes by police officers. Other factors can drive up the risk of violence at any given call, from racial profiling to insufficient housing to poor mental health systems.

But guns are the one uniquely American factor that can escalate a police call.

Addressing the root causes of crime means addressing guns

Ideally, policing in the US would look very different. Several experts pointed to the principles laid out by Sir Robert Peel, who established the London Metropolitan Police Force in 1829, emphasizing crime prevention, rather than reaction to crime, and efforts to build public support. They called for evidence-based police training, stronger accountability measures, more use of research-backed crime prevention strategies, and greater focus on violence and interpersonal conflicts, leaving lower-level offenses and incidents to unarmed officials when possible.

Some activists have gone further, with calls to “defund the police” and redirect savings to other programs that address root causes of crime, such as poverty, mental health care, and housing.

But guns are also a root cause of violence, and not addressing it makes police reform approaches less likely to succeed as intended. What happens, for instance, when staff members of an unarmed team tasked with responding to nonviolent calls get shot? Do they ask for police escorts or backup — diminishing the purpose of the reform? Do they ask to be armed — also defeating the purpose of the reform?

University of Missouri St. Louis criminologist Richard Rosenfeld said that the latter has happened before: Probation and parole officers frequently started out unarmed but over time have armed themselves because, in their view, “they were endangered by their armed clients.”

That doesn’t mean other reforms aren’t worth trying, experts said. But they are likely to be limited in scope and reach by the reality of guns in America.

In some cases, police reform may even conflict with the task of addressing root causes — making it less likely the reform can succeed on all fronts. For example, a lot of attention has gone to police’s involvement in routine traffic stops, with Philadelphia recently banning officers from stopping drivers for low-level offenses.

But it turns out traffic stops are also a big source of the guns police take off the streets. Hall’s analysis for the Manhattan Institute found 42.3 percent of the NYPD’s gun arrests in 2020 were during vehicle stops. Many of these calls can start over a broken taillight or reckless driving, only for the officer to discover an illegal firearm. And, unfortunately, it’s really hard for officers to know which stops will go in this direction; you can’t tell who’s carrying a gun simply by looking at the vehicle or driver.

It also may not be that police’s footprint in US society — and all the costs that brings — are taking up resources from better solutions, but that police are necessary because US society has failed to address root causes of crime and violence first. As University of Pennsylvania criminologist Aaron Chalfin told me, “The police are the residual claimants on all the stuff that no one else is willing or able to deal with. We put them in that position.”

In the case of guns, police are frequently needed because a country awash with firearms requires some sort of armed presence to keep people safe. Only once that abundance of guns is reduced can the police safely retreat.

Stricter gun laws could help. A 2016 review of 130 studies in 10 countries, published in Epidemiologic Reviews, found legal restrictions on owning and purchasing guns tended to be followed by a drop in gun violence — a strong indicator that reducing access to guns can save lives. In the US, there’s particular evidence for requiring a license to purchase and own a firearm. But for political and cultural reasons, America has resisted new, serious national measures for decades, letting firearm purchases continue with few if any checks.

This has contributed to the dynamic of police acting as American society’s backup solution, which is what has saddled officers with so much responsibility to begin with. It’s not that cops wanted more duties. In my years of reporting on this issue, many officers have told me the opposite: that they were called to fill in — by lawmakers and the public — when society had already failed.

To describe these extra duties, police officers “use different terms — nonsense, bullshit, whatever they want to call it,” Sierra-Arévalo, the sociologist, said. “That’s a consistent thing: They don’t think they should be going to a lot of these things.”

America’s tremendous number of guns is at the center of all of this, exacerbating many of the country’s problems by adding a higher risk that any situation can escalate into deadly violence. Once this problem is seen, it’s hard to unsee; it makes it clear why police are responding to so much of the “nonsense” and “bullshit” in the first place.

Doing something about the guns may be the only hope of truly altering that reality — and allowing more police reform.

All of America’s school-aged children can now get the Covid-19 vaccine. But should kids be required to get it?

Schools in every state, after all, already mandate vaccines for a range of diseases. These mandates have a long history in the US, with some states requiring immunization in schools as early as the 19th century. One goal of the mandates is to stop the spread of potentially deadly diseases, but another is to prevent outbreaks from disrupting the classroom as kids get sick and stay home.

Covid-19 has very much disrupted schools in the past year and a half. And while the coronavirus’s risk to kids is relatively low, it’s still killed nearly 600 children in the US, according to federal data. Kids can also spread the virus to people who are more vulnerable, including parents, grandparents, teachers, and other school staff.

The research on past school and other mandates, meanwhile, suggests that mandates successfully increase vaccination rates among children. More than 80 percent of kids are inoculated for other diseases, including polio, measles, and chickenpox, by age 2 — so serious outbreaks are very rare and almost never disrupt schools.

All of that, plus the high effectiveness of the Covid-19 vaccines, adds up to a compelling case that schools should require Covid-19 vaccines for students.

Yet there are reasons that schools might want to wait. The Pfizer/BioNTech Covid-19 vaccine is authorized for kids only for emergency use. It’s not fully approved, which creates some legal uncertainty around school mandates. There are also legitimate questions about the possible side effects for kids, including myocarditis (inflammation of the heart muscle). And while the research generally supports mandates, it also suggests that mandates are less effective if there’s not sufficient public buy-in.

To date, only California has said it will require Covid-19 vaccines for schoolchildren once the vaccines get full approval from the Food and Drug Administration.

“I don’t expect schools to move totally in this direction until [full approval],” Jen Kates, director of global health and HIV policy at the Kaiser Family Foundation, told me. “Some may, but they’ll get pushback.”

The process could ultimately work like an expedited version of what we saw earlier this year: When the shots were approved for adults, officials, by and large, relied on enthusiasm for the inoculations and persuasion to get people vaccinated. Then they tried to incentivize shots through financial payouts and other benefits, albeit with disappointing results. Only once those measures proved to be not enough (about 70 percent of people 18 and older in the US are fully vaccinated) did employers, businesses, and different levels of government start mandating the vaccines.

Schools should be ready for this same chain of events. They should want to get kids vaccinated — it’s the best way to guarantee Covid-19 will stop disrupting the classroom. Chances are, though, that persuasion and incentives won’t be enough. And if that’s the case, mandates are a proven way to get vaccination rates up.

School mandates work

The empirical research on school vaccine mandates isn’t very expansive. But there are some studies, and they’re consistently positive for vaccination requirements.

A review of the research published in CMAJ Open in 2019 found that school mandates are “largely associated with increased vaccination coverage.” The review called for more studies, particularly with methodology that can better discern causation from correlation. But the studies reviewed, in elementary and middle school settings, showed that mandates seem to boost vaccination rates.

The chickenpox vaccine offers a recent example. The vaccine was approved in 1995, but initial uptake among children wasn’t great — in part because, like the coronavirus in kids, chickenpox carries a relatively low risk of death or serious complications for younger children. So in the late 1990s and 2000s, as vaccination rates stagnated, states began mandating the shot.

It worked. A 2005 study in Vaccine found that states with chickenpox vaccination requirements for day cares and school entry had greater coverage: 85 percent in the states with mandates compared to 77 percent for those without. The researchers also found that states with mandates didn’t appear to have higher vaccination rates prior to the requirements, suggesting the mandate is what made the difference.

A 2011 study in the Journal of Health Economics looked at the impact of school and day care mandates, broken down year by year. They found that the mandates increased vaccination rates, with the strongest effect in the second year after the mandate began.

Studies have also found evidence for mandates in other settings. A 2015 review of the research in Human Vaccines and Immunotherapeutics found that mandates in health care settings were the most effective intervention for boosting vaccination rates compared to softer requirements, increased awareness, and better access.

In recent weeks, there’s also been real-world evidence that Covid-19 vaccine mandates in particular are effective. As more workplaces and government agencies have mandated the shots, the requirements have consistently pushed up vaccination rates — to 90 percent or more in specific settings — while leading to very few, if any, resignations.

One telling example: Novant Health in North Carolina initially suspended 1 percent of its workforce — nearly 400 people — for not getting the vaccine, only for more than half of those workers to get the shot and go back to work within a week. What was once vaccine hesitancy and apathy quickly melted away as people got immunized.

Schools might want to wait

Despite the evidence, some experts remain skeptical that schools nationwide will embrace mandates — and note that there are some legitimate reasons to wait.

First, there’s the legal concerns. Since the vaccines are only authorized for emergency use for kids and lack full approval, there’s a worry that mandates now would fall to legal challenges.

Second, there are genuine concerns about the side effects of the vaccines. While all the experts I spoke to said they would get their kids vaccinated, they acknowledged legitimate concerns about the Pfizer vaccine causing myocarditis, particularly in boys. Coupled with the data showing that kids are at relatively low risk of Covid-19 to begin with, it’s not unreasonable for parents to wonder if the benefits of vaccines outweigh the risks.

An analysis by the Food and Drug Administration estimated that once Covid-19 is under greater control — which is not the case today but will be in the future — the vaccine could lead to higher hospitalization rates for children than the SARS-CoV-2 virus itself. The FDA suggested that the vaccine would still be worth it even in that scenario; the vaccine-linked myocarditis cases are almost all minor and resolve with very few, if any, lasting problems, while Covid-19 is far more likely to cause serious myocarditis and other significant health issues, including death, in the first place.

Still, the data presents a genuine challenge for school mandates. “You’re going to get pushback from parents that you’re actually putting their child at more risk by requiring them to be vaccinated,” Céline Gounder, an epidemiologist at New York University, told me.

The experts I spoke to said their own concerns were addressed by Pfizer moving to use a smaller vaccine dose for kids — those ages 5 to 11 get one-third of the dose given to people 12 and up. But myocarditis cases and other side effects continue to be something to watch for as vaccines are administered and more real-world data comes in.

Finally, there’s public buy-in. A recent survey from the Kaiser Family Foundation found just 27 percent of parents of kids 5 to 11 are eager to get their kids vaccinated, with 33 percent planning to wait and how the vaccines work and 30 percent saying they “definitely won’t” get their kids vaccinated. That’s more than six in 10 parents unwilling to get their kids vaccinated right away.

The level of skepticism can make mandates less effective. CMAJ Open’s 2019 research review found that mandates for HPV vaccines — which, like the Covid-19 vaccines, have been caught up in political controversy and safety concerns — “were notably ineffective.”

One way to build public support may be to tie vaccination rates or access to the vaccines — after a certain period of time — to the end of Covid-related restrictions, such as closures and masking. Some research suggests people are more likely to get vaccinated if it allows them to ease up on restrictions.

Monica Gandhi, a doctor and an infectious disease expert at UC San Francisco, told me that she rescinded her support for California’s school vaccine mandate after finding out it wasn’t linked to the end of school masking requirements. But she’d support a vaccine mandate if it came with an off-ramp for other restrictions.

“It’s not that I think children shouldn’t be vaccinated, because I do,” Gandhi said. But “there needs to be an off-ramp for children masking in schools.”

The vaccines are still the way out of the pandemic, and the ability to vaccinate kids is a crucial step to getting the world back to something closer to the pre-Covid normal. But the authorization of vaccines for kids is only the first part of that final step — and mandates will very likely be needed to finish the job.