Cedars-Sinai infectious disease experts are urging travelers to check vaccination records before going abroad this summer because polio still circulates in parts of Europe, Asia and Africa. For vaccinated travelers, the risk is minimal, but older adults may need to think about a booster before visiting places where transmission remains possible.
Michael Ben-Aderet, associate director of Hospital Epidemiology at Cedars-Sinai, said, "More than anything, it’s a good reminder that staying up to date on vaccinations is critical to staying safe and healthy while traveling." Travelers who are planning trips now have a narrow window to make that happen, since the polio vaccine does not deliver its full benefit until four weeks after vaccination.
Polio outside the U.S.
Polio was eliminated in the U.S. more than four decades ago, and almost everyone in the U.S. received the vaccination series as a child. That leaves many travelers with some baseline protection already in place, but Cedars-Sinai’s reminder is aimed at the people who may not know whether that protection still fits their current travel plans.
In recent years, roughly 30 countries in Africa, Europe and Asia, including the U.K. and Germany, have shown signs of the virus circulating. Public health officials in the U.K. have detected the virus in wastewater tests, showing that poliovirus can still turn up outside the places most travelers associate with it.
Booster timing for travelers
The practical question for travelers is whether a booster belongs on the pre-trip checklist. Cedars-Sinai says older adults who worry their immunity may have waned over the years may consider one before visiting regions where transmission remains a possibility, and the vaccine has minimal side effects.
Travelers begin receiving some protection immediately after vaccination, but full benefit takes four weeks. That timing matters most for people booking summer trips late, because a last-minute shot may help, but it will not be at full strength before departure.
Measles in Europe and Asia
Cedars-Sinai also points travelers toward a second vaccine issue that can matter even more in crowded or enclosed spaces. Measles is far more contagious than polio, spreads through airborne particles from an infected person’s cough or sneeze, and can stay in the air for up to two hours after that person leaves.
The reminder lands in a year when U.S. measles cases in 2026 have exceeded 2,220, with outbreaks in Pennsylvania, Virginia and Utah. For summer travelers, that makes a vaccination record check less like routine paperwork and more like a quick pre-trip decision with a real deadline attached.
