Coronavirus disease 2019 (COVID-19) has been the greatest disruption to the movement of people since World War II. Many who had plans—and permission—to move permanently from one country to another have seen their transition put on hold. Worldwide, the flows of tourists, business and professional travelers, and students are all affected. But those most vulnerable to the virus and virus-related policies are low-paid migrant workers who have lost their jobs, and refugees or displaced people. Their lives were precarious even before the pandemic spread. Migrant workers suffer as they struggle to return home with little or no money, often in the face of travel restrictions and suspension of transport links. In India, after Prime Minister Modi imposed a country-wide lockdown on 24 March, hundreds of thousands of internal migrants crowded the roads on foot, creating the very conditions that the lockdown was meant to prevent. Many foreigners are being summarily expelled, such as in India and Saudi Arabia. Others are stranded in foreign countries. Losing jobs creates a cascade of other losses for migrant workers—of legal status and access to health care and other public services. Only a few places, including Portugal and New York state, have opened their health care systems to migrants regardless of legal status (as Thailand has done since 2013 in response to the AIDS epidemic and other infectious diseases brought to the country by migrant workers). These migrants' families back home will suffer too, from the loss of remittances that fund health care, housing, education, and better nutrition. The departure of temporary migrant workers also creates risks for the native population. Agricultural producers in Europe, for example, are predicting crippling labor shortages this spring and summer. Refugee camps are densely packed—the largest one in the world, in the Cox's Bazar District of Bangladesh, has three times the population density of New York City, without a single high-rise building. Social distancing is impossible in such a setting. Clean water for handwashing is scarce. Medical resources are thin, although humanitarian agencies are ramping up hand-washing stations, protective gear, isolation units, and ambulance services. Conditions in European “reception centers” for refugees and asylum seekers, like that near Moria village on the Greek island of Lesvos, are worse than in many refugee camps in poor countries. Moria holds about 22,000 people in a site built for 3000. There are 1300 residents per water tap. So far, the only refugee camps known to have confirmed cases of COVID-19 (Ritsona and Malakasa) are in Greece. Perhaps the most critical resource is information. The 120,000 people in Jordan's two main refugee camps are taking preventive measures (avoiding crowds) after a blizzard of electronic messages from the United Nations Refugee Agency (UNHCR). For most refugees and poor migrants who live in urban areas rather than camps, access to authoritative information is a lifeline. But many, especially in remote rural areas, do not have internet access. In the Cox's Bazar camps, the government forbids mobile phones. In every country, rich or poor, the provision of accurate and timely information is among the most urgent responsibilities of governments. Unlike most natural disasters, COVID-19 has so far affected rich and upper-middle-income countries (including China, Iran, Turkey, Brazil, and South Africa) more than poorer ones. But that will quickly change in countries whose health care systems are ill-equipped to cope. Displaced people and poor migrants are often the last in line for health services. The virus cannot be suppressed if vulnerable migrants and refugees are not integrated into COVID-19 responses. UN organizations, particularly the UNHCR and the International Organization for Migration, and a host of national and global humanitarian nongovernmental organizations (NGOs), are working frantically with national governments to stop COVID-19 from taking hold in refugee settings and to educate migrant populations and host communities on prevention. The special appeals have gone out: The UN Global Humanitarian Response Plan for COVID-19 is asking for $2.01 billion dollars to cover the actions of all its agencies and NGO partners. These organizations have experience in suppressing epidemics in deprived settings: ebola, cholera, dengue fever, and more. It is vital to everyone's safety that governments give them the funds they need in this global crisis.