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COVID-19 vaccines were widely deployed in various countries beginning in December 2020. Treatments include novel antiviral drugs and symptom control. Common mitigation measures during the public health emergency included travel restrictions, lockdowns, business restrictions and closures, workplace hazard controls, mask mandates, quarantines, testing systems, and contact tracing of the infected.
COVID‑19 transmission occurs when infectious particles are breathed in or come into contact with the eyes, nose, or mouth. The risk is highest when people are in close proximity, but small airborne particles containing the virus can remain suspended in the air and travel over longer distances, particularly indoors. Transmission can also occur when people touch their eyes, nose or mouth after ...
The United States of America ( USA or U.S.A. ), commonly known as the United States ( US or U.S.) or America, is a country primarily located in North America. It is a federation of 50 states, a federal capital district ( Washington, D.C. ), and 326 Indian reservations. [j] Outside the union of states, it asserts sovereignty over five major unincorporated island territories and various ...
A map of the United States showing its 50 states, federal district and five inhabited territories. Alaska, Hawaii, and the territories are shown at different scales, and the Aleutian Islands and the uninhabited northwestern Hawaiian Islands are omitted from this map.
U.S. state. In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sovereignty with the federal government.
Washington, D.C., formally the District of Columbia and commonly called Washington or D.C., is the capital city and federal district of the United States. [13] The city is on the Potomac River, across from Virginia, and shares land borders with Maryland to its north and east. Washington, D.C., was named for George Washington, a Founding Father ...
The United States Department of Homeland Security ( DHS) is the U.S. federal executive department responsible for public security, roughly comparable to the interior or home ministries of other countries. Its stated missions involve anti-terrorism, border security, immigration and customs, cyber security, and disaster prevention and management.
