CHICAGO (CBS) — Four more states have been added to Chicago’s COVID-19 travel advisory, meaning unvaccinated travelers from the vast majority of the United States are now urged to either quarantine or provide a recent negative COVID test when they arrive in the city.

Colorado, Maryland, Nebraska, and South Dakota are the latest states to join the list as the delta variant of the virus continues to drive a new surge in cases nationwide. Washington, D.C., was removed from the list on Tuesday, as its caseload fell below the threshold for the city’s travel advisory.

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The travel advisory list now includes 43 states and two territories: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Delaware, Florida, Georgia, Hawaii, Idaho, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming, Puerto Rico, and the Virgin Islands.

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Unvaccinated people traveling from states or territories on the list are asked to obtain a negative COVID-19 test result no more than 72 hours before arriving in Chicago, or to quarantine for 10 days when they arrive.

People who are fully vaccinated are exempt from the advisory to quarantine or test negative for the virus.

City officials said all travelers, regardless of vaccination status, are still subject to the city’s indoor mask mandate, as well as the requirement to wear a mask on planes, buses, trains, and other forms of public transportation.

States are added to the travel advisory list when they surpass 15 coronavirus cases per day per 100,000 residents.

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The list is updated every Tuesday.

CBS 2 Chicago Staff