IF, for some reason I had tickets that couldnt be changed or refunded and I decided going to my initial destination would be a bust due to closings of the sights I would look at alternative side trips that had a different emphasis. Fortunately I love fishing, so I could land in Budapest then hop Wizzair to Sarajevo and go up in the mountains with my fly rod. The fish dont know about COVID-19. There may be similar options for others to save their trip; go on a driving tour through the Alps for instance or lay on a beach in Budva.
FYI, not to be negative, just well informed.
Global Level 3 Health Advisory - Reconsider Travel
The Department of State advises U.S. citizens to reconsider travel abroad due to the global impact of COVID-19. Many areas throughout the world are now experiencing COVID-19 outbreaks and taking action that may limit traveler mobility, including quarantines and border restrictions.Even countries, jurisdictions, or areas where cases have not been reported may restrict travel without notice.
For the latest information regarding COVID-19, please visit the Centers for Disease Control and Prevention's (CDC) website.
You are encouraged to visit travel.state.gov to view individual Travel Advisories for the most urgent threats to safety and security.Please also visit the website of the relevant U.S. embassy or consulate to see information on entry restrictions, foreign quarantine policies, and urgent health information provided by local governments.
Travelers are urged to enroll in the Smart Traveler Enrollment Program (STEP) to receive Alerts and make it easier to locate you in an emergency.The Department uses these Alerts to convey information about terrorist threats, security incidents, planned demonstrations, natural disasters, etc.In an emergency, please contact the nearest U.S. Embassy or Consulate or call the following numbers: 1(888) 407-4747 (toll-free in the United States and Canada) or 1 (202) 501-4444 from other countries or jurisdictions.
If you decide to travel abroad:
Review and follow the CDC's guidelines for the prevention of coronavirus.
Check with your airlines or cruise lines regarding any updated information about your travel plans and/or restrictions.
Visit travel.state.gov to view individual Travel Advisories for the most urgent threats to safety and security.
Visit our Embassy webpages on COVID-19 for information on conditions in each country or jurisdiction.
Visit the Department of Homeland Security's website on the latest travel restrictions to the U.S.