Poland will allow some vaccinated travelers to enter without quarantine
Travelers who have been vaccinated against COVID-19 are exempt from mandatory quarantine in Poland, providing they come from the countries it is currently admitting. Admission to Poland is currently restricted to citizens or legal residents of European Union countries, Iceland, Liechtenstein, Norway, Switzerland, Georgia, Japan, Can
Sweden Officially Reopens To U.S. Tourists
Sweden has reopened to U.S. travelers as of June 30th, presenting American tourists with another European destination to visit this summer. The country had banned all non-essential travel from outside EU/EEA nations since March 2020. After February 2021, the ban included a requirement of presenting a negative COVID-19 test upon arrival. If you want to travel to Sweden, you need to be covered by one of the entry ban exemptions and prove that your travel is essential and
COVID-19: Traveling to Romania - quarantine requirements & national restrictions
The National Committee for Emergency Situations (CNSU) updates the list periodically (usually once every two weeks). The latest list (valid starting January 19) includes almost 50 countries/areas, such as the UK, the US, Portugal, Sweden, Denmark, Spain, Italy, South Africa, France, the United Arab Emirates, and Canada.