We’re used to flu season in the U.S. Generally, it runs from October through March, and some seasons run into April or even May. But international travelers may find that their destination has a much different flu season. Take a look at the map below.
climate zones
You’ll notice that the world is divided into climate zones. There is a northern hemisphere temperate zone and a southern hemisphere temperate zone. And then there is a tropical zone that extends into both hemispheres.
In the southern hemisphere temperate regions, flu season is typically April through September. Countries in the northern temperate zone will have the same flu season as the U.S.
In the tropics, however, flu activity occurs throughout the year. You can find a list of countries that are considered in the tropics here: Tropical countries
So, what does this mean for you as an international traveler? Depending on your destination, you could be traveling to an area with a lot of flu activity even though it is low in the U.S. Protecting yourself involves a couple of strategies:
1. Get an annual flu vaccine. You can usually find flu vaccines in the U.S. from about September through May or possibly June (each year’s batch expires in June of the following year). If you got the vaccine in November and later find out that you are traveling to South Africa in June (southern temperate zone), there is no information on possible benefits of getting revaccinated, so the CDC does not recommend it. If you did not get vaccinated during the U.S. flu season and will be traveling to an area of high flu activity but there are no more flu vaccines available in the U.S. you might consider getting vaccinated at your destination if you will be there longer than 2 weeks (it takes about two weeks to develop immunity).
2. Practice flu precautions: frequent hand-washing with soap and water or use of hand sanitizer with at least 60% alcohol. Also, don’t cough or sneeze into your hands…sneeze into your upper sleeve instead. Try to avoid sick people if you can.