Are you being nudged to get your flu shot? If you’re a healthy teenager who takes care of yourself, you may think you are naturally protected from the flu. In a recent survey by Student Health 101, 38 percent of high school students who responded said they believe that healthy lifestyle behaviors, like eating well and exercising, will help protect them from flu infection this season. Is this true?
Only to a relatively minimal degree. Healthy behaviors serve us very well in many ways—but they cannot substitute for a flu vaccine. It’s tempting to believe otherwise, because we often encounter inaccurate and misleading messages about how immunity works. You have probably come across claims that a particular food product or dietary supplement can “boost” your immune system. Few of these claims are backed by research. What they boost instead is our false sense of protection against a common and contagious virus.
The flu is at best an inconvenience that disrupts students’ school success, extracurriculars, and relationships. At worst, it’s a serious and life-threatening disease, even to otherwise healthy teens.
1. Exposure to the flu is almost inevitable
“There’s nothing you can do to resist the flu besides getting vaccinated,” says Dr. Paul Offit, professor of vaccinology and professor of pediatrics at the University of Pennsylvania School of Medicine.
“You can not go outside, you can stay by yourself in your room, you can live in a protective bubble. But if you enter the world, you’re going to be exposed [to influenza viruses]. You can’t avoid getting infected just by having a healthy immune system, although it will give you the best chance of fighting a disease. And you’re not going to have natural immunity before you’ve been exposed.”
It’s true that if we are always stressed out, exhausted, or malnourished—as many high school students are—our immune function probably won’t be as good as it could be. “Does this increase our chance of getting severely infected? Yes,” says Dr. Offit.
2. Why we can’t “boost” our immune system
It may seem logical that if we can lower our immunity by becoming physically and emotionally run-down, we can also strengthen it by taking care of ourselves. Surprisingly, that doesn’t follow—at least, not in the ways we might expect.
While healthful habits help us in all sorts of ways, they cannot equip us with the antibodies that could fight off a specific virus. Reasonably healthy people already have normal immune function, and this is not “boosted” by taking extra care of ourselves.
“There’s no going above normal,” says Dr. Ben Kruskal, chief of infectious diseases at Harvard Vanguard Medical Associates, Boston. “You can only fill your gas tank as full as it gets. If you pay a bit more for fancy gas that will maybe give you slightly better mileage or speed. But it can’t turn your Toyota into a racecar.”
3. Healthy habits don’t generate antibodies
The science highlights the unique role of vaccines. “What we know now is that [healthy behaviors like] good diet and good sleep are not enough to prevent all illnesses. Influenza and other vaccine-preventable infections are good examples. If the immune system has not seen a particular infection before, it cannot mount the high-quality, fully protective immune responses needed for protection,” says Dr. Timothy Lahey, associate professor of medicine and associate professor of microbiology and immunology at the Geisel School of Medicine, Dartmouth College, New Hampshire.
“Sure, it helps not to be malnourished, but a good diet is no substitute for an effective vaccine. The influenza epidemic of 1918 is a great example: The highest rates of death and disease occurred among young healthy people who, unlike their elders, had no immunological memory of that strain of influenza [because their immune systems had not encountered it before] and therefore perished in droves.”
Healthy behavior + vaccine = protection
“Fortunately, in the 21st century people with good common sense do not need to choose between a healthy diet and the miracle of vaccines,” says Dr. Lahey.
“Good diet and sleep [help] prevent illnesses, and so they are good to get. To add to that protection, vaccines can stave off lethal infections like influenza, measles, tetanus, and human papillomavirus, which can afflict even the most well-fed and well-rested person.”
Where to get the flu vaccine
If you haven’t gotten the flu shot yet this year, it’s not too late. Go to your school nurse, family doctor, county health department, or your local pharmacy to ask for it. Most insurance plans cover the flu shot for free or make it very affordable. Without insurance, the flu shot usually costs about $20–$40 at standard pharmacies.
Ben Kruskal, MD, chief of infectious disease, Harvard Vanguard Medical Associates, Boston.
Tim Lahey, MD, associate professor of medicine and of microbiology and immunology, Geisel School of Medicine, Dartmouth College, New Hampshire.
Paul Offit, MD, Maurice R. Hilleman Chair of Vaccinology, University of Pennsylvania School of Medicine.
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