As the novel coronavirus has spread, so, too, has fear: Beijing has imposed a travel ban on 16 cities, quarantining more than 50 million people, and several countries, including Australia and Singapore, have also imposed travel restrictions. The World Health Organization declared a public health emergency of international concern. Anti-Chinese sentiment, too, has spread rapidly: In France, a newspaper headline warned of a “Yellow Alert,” and restaurants in South Korea, Hong Kong and Vietnam have reportedly refused to serve Chinese customers. In the United States, customers are avoiding cities’ Chinatown neighborhoods, and students report anti-Chinese sentiment growing on their college campuses.

Initially, the U.S. government adopted a relatively measured response, even as political commentators and some members of Congress demanded that the United States ban all travel from China. It resisted travel bans in lieu of warning people to avoid nonessential travel to China and screening passengers from China at 20 international airports. Its decision Friday to deny entry to non-nationals who have recently traveled to China and quarantine Americans who are returning from that country marks a significant, and potentially counterproductive, escalation in the U.S. response to the coronavirus crisis.

Although this may assuage critics who insisted that the administration take more aggressive action, history and epidemiology warn us that such measures are unlikely to work. Respiratory diseases are not easily contained by travel bans or quarantines. Rather than contain an epidemic, harsh, coercive policies often scapegoat already-marginalized populations and intensify panic rather than quell it.

History offers ample reasons to be wary that authorities may resort to discriminatory measures in the face of a frightening disease. When bubonic plague came to San Francisco in 1900, for example, the city twice enacted racially motivated, scientifically dubious measures. First, health officials required that Asian residents be inoculated with an experimental vaccine before traveling outside the city. After a federal court, in a rare example of judicial intervention during a public health panic, struck down that measure, the city established a quarantine around a neighborhood where many Chinese residents lived, enforcing it only against Chinese residents. That quarantine was also found to be unconstitutionally discriminatory. Decades later, HIV similarly provoked discrimination against groups perceived to be at the highest risk. As children such as Ryan White were kept out of school and well-known commentators demanded widespread quarantine, the Coast Guard picked up asylum-seeking Haitians and quarantined them at Guantanamo Bay, Cuba. Given that HIV was already widespread, as Judy Rabinovitz, a lawyer with the American Civil Liberties Union, noted at the time, “there can be no pretense that this can be to the public health benefit of the United States.”

Our nation’s most recent disease panic further illustrates what can go wrong when fear rather than science drives the government’s response to an outbreak. In 2014, when Liberian citizen Thomas Eric Duncan was diagnosed with Ebola while visiting relatives in Dallas, and two nurses treating Duncan contracted the illness, a full-blown panic erupted; demand for coercive responses grew. Despite assurances by the Centers for Disease Control and Prevention that blood and other bodily fluids were the primary modes of transmission, the news media fueled public fear about casual transmission. Governors responded by quarantining travelers who exhibited no symptoms of Ebola. Although she was not infected, Kaci Hickox, a nurse, was involuntarily detained in a tent outside Newark International Airport after arriving from West Africa, where she had treated patients. After Hickox told her story to the media, New Jersey Gov. Chris Christie (R) allowed her to travel to Maine, where state officials sought to quarantine her. A federal court later dismissed her constitutional challenge to New Jersey’s actions, and a federal court in Connecticut likewise dismissed a case brought by several people quarantined in that state. (An appeal of that case is pending.)

The Ebola scare had lasting implications for how the federal government might respond to future outbreaks. In 2017, the CDC published new federal quarantine regulations. Federal law had long given CDC broad powers to restrict international and interstate travel and apprehend and detain people who are thought to have a quarantinable disease (a designation established by presidential order). Despite the breadth of that authority, the CDC had generally left infection control, at least within the country, to state and local health departments. Indeed, the CDC’s own prior quarantine regulations were remarkably thin, offering little guidance as to when and how the agency should exercise its authority. The updated regulations provide far greater specificity, authorizing the CDC to collect detailed information about travelers’ health status, and detain or bar travel (including interstate travel) of people who have — or are “reasonably believed” to be infected with — a quarantinable disease. The level of detail in these provisions appeared to signal that the CDC was prepared to assume a more robust domestic rule in future outbreaks, as it did last week

The regulations also created several layers of internal administrative review. Critics, including one of us, worried that the due-process review provisions were inadequate, allowing people to be detained for relatively long periods while the review proceeded. In addition, the regulations do not provide for review by an independent decision-maker. They also do not limit detentions and travel bans to situations in which they are the least restrictive alternative, a standard that some courts have held to be constitutionally compelled. Also absent are protections from deportation and income replacement for people who are quarantined. Both protections may be critical to ensuring that people are willing to comply rather than seek to evade quarantine orders. In addition to these lapses, the regulations have few safeguards to prevent federal officials from wielding their public health powers in ineffective, potentially abusive ways. And as the Ebola lawsuits show, the public cannot count on the courts to protect them from public health overreaches. When panic strikes, judges are often loath to intervene.

What, then, can protect us from plagues and panics? Although there are no simple panaceas, there are two durable antidotes. One is a strong and resilient health-care system that the public can easily access, and in which public health laboratories and hospitals have a strong surge capacity. Unfortunately, as hospitals close and the number of uninsured Americans increases, our health-care system is facing significant strains. The other is trust: In times of peril, it’s critical that the public have faith in the expertise and good intentions of health officials. When officials are distrusted, or rumors are given as much credence as expert advice, panic is likely to worsen, increasing the chance that the authorities may impose ineffective, discriminatory policies.

Unfortunately, the latter antidote may be in especially short supply today. Although overall trust in science remains high, faith in government is perilously low. As scientists are leaving the federal government, well known and trusted voices in public health are missing. Meanwhile, partisanship and tribalism seem to exert more and more influence on how Americans view the challenges we face as a nation. In such an atmosphere, public health officials may lack the tools to calm the public and guide it through a health crisis. That, in turn, may enhance the risk that they will employ coercive and discriminatory measures, based more on fear of others than on epidemiological best practices. If history is any guide, such efforts are doomed to make a bad situation worse.