RELATED: Unvaccinated People Will Be Barred From This, Starting Feb. 28. On Feb. 7, Australia’s Prime Minister Scott Morrison announced that the country would finally be reopening its borders to international travelers nearly two years after it closed itself off to almost all non-citizens as a result of the COVID pandemic, The New York Times reported. But there’s one stipulation to Australia’s opening: You have to be fully vaccinated to visit. “If you’re double vaccinated, we look forward to welcoming you back to Australia,” Morrison said in a news conference. Starting Feb. 21, vaccinated tourists, business travelers, and all other visa holders will be allowed to enter the country, according to Karen Andrews, Australia’s home affairs minister. The only exception to the vaccine mandate will be visa holders. But those unvaccinated travelers will face strict quarantine requirements and need a travel exemption as well. This new ruling also won’t open the entirety of Australia to all international travelers, because individual states control their own borders and can implement their own restrictions, per The New York Times. As of right now, the country’s two most populous states, New South Wales and Victoria, have no quarantine requirement for vaccinated travelers, but Western Australia is choosing to keep its borders limited to only certain visitors.ae0fcc31ae342fd3a1346ebb1f342fcb RELATED: For more up-to-date information, sign up for our daily newsletter. Other countries, such as Japan and New Zealand, are choosing to continue to keep their borders closed to all foreign travelers in order to contain the spread of COVID, according to The New York Times. Meanwhile, for countries like Argentina, Bermuda, Canada, and Singapore, only unvaccinated tourists are still being denied entry. “Make sure you are up to date with your COVID-19 vaccines before you travel internationally,” the CDC advises. “Check your destination’s COVID-19 situation and travel requirements before traveling. Countries may have their own entry and exit requirements.” And while most European countries are allowing in fully vaccinated U.S. travelers, these requirements are getting more stringent over time. On Dec. 21, the European Commission, which is the European Union’s (EU) executive branch, voted to adopt rules that establish a binding acceptance period of nine months (270 days) for vaccination certifications when traveling between EU countries. So, as of Feb. 1, any fully vaccinated travelers who received their initial dose or doses more than 270 days before traveling to Europe cannot travel between countries in the union unless they have gotten their booster. If you received your initial vaccination before May 1, 2021 and have not received your additional dose, you’re effectively barred from traveling to EU countries—despite being considered fully vaccinated by the standard definition. This includes 27 different countries: Austria, Belgium, Bulgaria, Croatia, the Republic of Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, and Sweden. And while Australia is currently only barring unvaccinated visitors—with no stipulation about boosters—many experts are warning that it’s unlikely booster mandates will stop in Europe. “We know that being boosted gives you much better protection, both against illness and serious illness. So it’s not surprising,” David Weber, MD, a professor of medicine, pediatrics and epidemiology at the University of North Carolina at Chapel Hill, told USA Today. “I think this will be an ongoing trend for countries that want to limit transmission.” RELATED: People Without a Booster Will Be Barred From This, as of March 1.