Flu (Influenza) Prevention

The best way to reduce the risk of flu and possible flu complications is to get vaccinated each year, learn about special considerations for travel.

You may need a flu vaccine before travel at other times of the year, depending on your destination .

  • In the Northern Hemisphere, flu season can begin as early as October and can last until April or May.
  • In the temperate regions (areas with seasons) in the Southern Hemisphere, flu activity typically occurs from April to September.
  • In the tropics, flu activity occurs throughout the year.
  • Travelers who are part of large tourist groups that include people from other parts of the world, such as on cruise ships, may be at risk.
  • People should get vaccinated at least 2 weeks before travel because it takes 2 weeks for immunity to develop after vaccination.
  • Getting a flu vaccine is very important for people at higher risk of serious flu complications.
  • If you already got your annual flu vaccine, you usually don’t need to get vaccinated again during the same season.

Do not travel if you are sick

  • If you are sick with flu-like symptoms, do not travel. Stay home until you are fever-free for at least 24 hours without using a fever-reducing medicine, such as acetaminophen.
  • Flu symptoms include:
    • Fever (Not everyone with flu will have a fever.)
    • Cough o Sore throat
    • Runny or stuffy nose
    • Muscle or body aches
    • Headache
    • Fatigue
    • Some people may have vomiting and diarrhea, though this is more common in children.

During Travel

During your trip, follow local guidelines and practice healthy habits.

  • Avoid close contact with sick people.
  • Wash your hands often with soap and running water, especially after coughing or sneezing.
  • If soap and water are not readily available, use a hand sanitizer that contains at least 60% alcohol. Cover all surfaces of your hands and rub them together until they feel dry.
  • Cover your mouth and nose with a tissue when you cough or sneeze and put the used tissue in the trash. If you don’t have a tissue, cough or sneeze into your upper sleeve, not your hands.

What to do if you feel sick

Most people with flu will recover without needing medical care. However, if you have severe illness or are at risk of getting serious flu complications, seek medical care.

A U.S. consular officer can help you find local medical care in a foreign country. To contact the U.S. Embassy or consulate in the country you are visiting, call Overseas Citizens Services at 1-888-407-4747 if calling from the U.S. or Canada, 00-1-202-501-4444 if calling from other countries. You can also visit the websites of U.S. Embassies, consulates, and diplomatic missionsExternal Link to find the contact information for the local U.S. Embassy of the country you are visiting.

Follow all local health recommendations

After Travel


If you traveled and feel sick, particularly if you have a fever, talk to a healthcare provider and tell them about your travel.

If you need medical care abroad, see Getting Health Care During Travel.