The year you were born--or at least whether you were born after or before the late 1960's--may influence which strain of bird flu might make you the most sick. For example, if you were born after the late 1960's, the strain you may be hardest hit by is from the H5 group.
After analyzing a lot of data on cases of bird flu, scientists figured out that the first human-based flu virus you're exposed to as a child determines which strain of bird-based influenza virus will be unlikely to cause you to become severely ill or die from in the future. That's because all the 18 known strains fall into two categories, and if, as a child, you're exposed to a virus that's in the same group as a virus you get later in life, you're protected from it.
People who were born before the late 1960's, were exposed to strains H1 and H2 as children Since H5 falls into the same group as those, if this applies to you, you have more protection from H5. Similarly, H3 is in the same group as H7, another new strain, so people exposed to H3 as children--people born after the late 1960s--have protection against H7.
Before this study, there wasn't any data that confirmed that being exposed to the flu gave people any future immune system benefits from new flus that moved from animals to people.
Sources and Further Reading:
- University of Arizona. "Your birth year predicts your odds if flu pandemic were to strike." ScienceDaily. (accessed March 12, 2017)
- James O. Lloyd-Smith et al. Potent protection against H5N1 and H7N9 influenza via childhood hemagglutinin imprinting. Science, November 2016 DOI: 10.1126/science.aag1322
- "Seasonal Influenza: Flu Basics." Centers for Disease Control and Prevention. October 31, 2016. Accessed March 12, 2017.
Thanks to Dr. Richard Hardy for his help in reviewing this script.