coronavirus disease 2019; economic aspect; health care access; health care policy; human; immigrant; Letter; migrant; pandemic; United States; virus transmission; vulnerable population; Betacoronavirus; Coronavirus infection; health care delivery; pandemic; socioeconomics; United States; virus pneumonia; Betacoronavirus; Coronavirus Infections; Emigrants and Immigrants; Health Policy; Health Services Accessibility; Humans; Pandemics; Pneumonia, Viral; Socioeconomic Factors; United States; Vulnerable Populations