“Just the flu” hospitalized 470,000 Americans in 2024 and caused 28,000 deaths.
Still thinking about skipping your flu shot? Before you decide, it helps to understand how this virus evolves, how difficult it is to develop a vaccine, and how well the vaccine does and doesn’t work.
How the Flu virus evolves
Most influenza viruses originate and mutate in Southeast Asia, where people, ducks, chickens, and pigs live in close proximity. These new viral strains first spread through the southern hemisphere and months later reach the northern hemisphere. Knowing this, international scientists analyze circulating strains and vaccine responses from the southern hemisphere each year to predict which viral mutations are most likely to dominate our upcoming flu season.
How well the vaccine works
The 2025 flu season data from the southern hemisphere (which has just ended) show that the current flu vaccine is about 50% effective in preventing hospitalizations and 45% effective in reducing total infections. Not perfect — but cutting your risk of a hospital stay in half is a worthwhile return on investment in time, comfort and health.
A few more facts
- Eggs: Between 500 million and 1 billion eggs are used annually to produce the world’s flu vaccines.
- Vaccination Rate: Only 43% of Americans receive the flu shot each year.
- Safety: The flu vaccine cannot cause influenza — it contains only viral fragments that train your immune system to recognize and fight the real virus.
- Personal note: In 1985, I skipped my flu shot. I caught the flu — and the experience was indistinguishable from being hit by a truck. The vaccine has been my ally for 40 years.
Is it yours?
Dr. Charlie Barnett is a contributor to KnoxTNToday, where he writes a weekly column, DocTalk, sharing his expertise on health and wellness management.
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