(NEXSTAR) – With more than half the country at least partially vaccinated, many are eager to venture forth from their homes and travel.

But before you hit the road, it’s important to remember that COVID-19 is still prevalent in the U.S., and airports bring together people from all over the place — not just from the region where the airport is located.

So what’s the worst contagion spot in an airport?

According to Dr. Peter Chin-Hong, an infectious disease expert at the University of California at San Francisco School of Medicine, “the main contagion spot is wherever noses and mouths get together.”

“It’s hanging out at the food court, hanging out at the gate — those are the hotspots,” he said.

Chin-Hong said you should also be conscientious of how you’re getting to and from the airport. Public transportation and ride shares are higher risk than traveling solo in a car, naturally.

The operating principle, Chin-Hong says, “is the more unknown mouths and noses you get together, the higher the risk.”

And in the airport, “it’s not just people from around the country, but the world. You don’t know where people have been, even if they had a negative test before [entering the country].”

The Centers for Disease Control and Prevention recently updated its domestic travel guidelines.

The organization recommends delaying travel until you are fully vaccinated, and to continue following its recommendations for safe traveling: wearing a mask, staying 6 feet away from others, avoiding crowds and washing or sanitizing your hands frequently.

International travel is a bit stickier. The U.S. Department of State has a list of countries that it does not recommend people travel to at this time, including:

  • India
  • Finland
  • Egypt
  • Croatia
  • Chile
  • Norway
  • Peru
  • Portugal
  • Seychelles
  • Germany
  • Greece

The State Department says to exercise “increased caution” in these countries:

  • Thailand
  • Belize
  • Rwanda
  • Sri Lanka
  • Vietnam
  • Montserrat

For more information on places you can travel, check your desired country’s local embassy website or the U.S Department of State website.