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Flu Prevention: 5 Critical Lessons from History and What They Mean Today

Here's how to be smarter about the flu, using history as your guide.

The flu returns year after year

In October 2009, the United States was in the thick of the swine flu pandemic. While pandemics don’t happen every flu season, public health experts can look  at efforts to control flu outbreaks in the past to see if they can limit the number of people who get sick or die in future pandemics. A pandemic is a global outbreak of a new influenza virus that has the ability to infect people and spreads around the world. (The 2019-2020 flu season is not a pandemic, according to the Centers for Disease Control and Prevention.)

Here are five lessons from the past that still stick with us today—especially during flu season. (If you do get the flu, here are 11 things to do at the first sign of the sniffles.)

What works: Shutting things down

In the so-called Spanish flu epidemic of 1918-1919, three waves of disease swept the world, killing approximately 50 million people, including 500,000 Americans. But Minneapolis and Milwaukee suffered fewer than 3 deaths per 1,000 people—less than half the rate in cities like Baltimore, Boston, and San Francisco. One reason: The Midwestern cities quarantined the sick, closed schools and churches, and banned public gatherings. Another city, Gunnison, Colorado, physically blocked the main roads into town. On the other hand, Philadelphia officials refused to ban meetings or parades on grounds of patriotism, and city newspapers downplayed the flu’s severity. The result: Philly had one of the highest death rates in the country. These measures have a cost, of course: Closing schools can force parents to miss work, which could hamstring the economy. Unless a flu outbreak is particularly severe, U.S. officials usually keep schools open as much as possible.

Take-home lesson: Ask your kids’ principal what would trigger a school closing. Strategize with friends about sharing child care if the need arises; talk to your boss about working from home.

What works: Vaccinating kids early

Who gets flu shots in the United States? Older people, of course—they’ve been the focus of flu vaccine campaigns since the 1960s. But an important way to increase their protection, ironically, is to vaccinate their children and grandchildren. The reason: An older person’s immune system doesn’t respond efficiently to the flu vaccine, so it’s only partially protective, according to the CDC. The same vaccine creates a much stronger immunity in the young. What’s more, kids are more likely than others to become silent carriers, transmitting the virus for up to ten days after symptoms disappear. Children, especially young ones, are at higher risk of flu complications.

Take-home lesson: It’s a good idea to get everyone in your family vaccinated, if they are eligible. Today, the CDC recommends that all people six months and older get an annual flu vaccine. People with chronic illnesses, like diabetes and heart or lung disease, and pregnant women, are at higher risk from complications of the flu, so should definitely get a flu shot. If you’re squeamish about the shot, here’s how to make it hurt less.

What works: A vaccine that can’t be fooled

Every year, people unlucky enough to be infected with the flu develop antibodies that will keep them safe if they’re exposed to the same virus in the future. But gradually, the virus mutates—sometimes enough to fool those antibodies and infect people again. As a result, virologists and public health officials are always playing catch-up. In February, they predict which strains of virus will circulate in the fall, and drug companies prepare vaccines to produce immunity to those specific strains. Inevitably, the predictions sometimes prove wrong. “It would be a huge advantage to have a universal vaccine,” says E. John Wherry, PhD, of the Wistar Institute in Philadelphia, a vaccine that would protect year in and year out, by aiming at pieces of the virus that don’t change. Like hundreds of scientists around the world, Dr. Wherry is trying to develop such a vaccine. It’s still a long way off, but a partial solution may already be available. When a vaccine is mixed with an adjuvant (a chemical mixture that stimulates the immune system), as has been done in studies of bird flu vaccine, it seems to protect against a variety of flu viruses. So even if the current virus mutates, an adjuvanted vaccine might still provide a shield.

Take-home lesson: Adjuvanted vaccines previously were not licensed in the United States. A flu vaccine with an adjuvant, FLUAD, was approved in November 2015. People 65 and over can receive this vaccine, according to the CDC. For people of all ages, the best way to boost your protection: Wash your hands often— the flu virus can survive up to 48 hours on surfaces. And get plenty of sleep; your immune system depends on it.

What works: A healthy respect for side effects

One balmy night in November 1976, 39-year-old June E. Roberts felt a coldness in her fingers as she tried to pay some bills. It was two weeks after she’d gotten a vaccine against the country’s first outbreak of swine flu. The next morning, the McLean, Virginia, tennis instructor couldn’t get out of bed. For more than a month, Roberts couldn’t eat, move her limbs, or even close her eyes. She recovered, slowly, but was never able to play tennis well again. Roberts had Guillain-Barré syndrome, a rare disorder in which antibodies attack the patient’s own nervous system. It can be triggered by infections that cause respiratory symptoms (like the flu) or diarrhea, and in rare cases, after the flu vaccine. During the swine flu outbreak in 1976, millions were vaccinated and Guillain-Barré syndrome affected more than 500 people and 25 died. (Most people recover but it can be potentially life threatening.) The episode highlights a point familiar to public health workers: Prevention sometimes carries risk.

Take-home lesson: The CDC has staff and computer tracking systems that look for possible problems with the vaccine, so if any unexpected dangers show up, they’re flagged quickly. But experts emphasize that it’s rare for any flu vaccine to have serious side effects. Both the 1976 and 2009 pandemics involved swine flu viruses, and the CDC carefully tracked the millions of people who were vaccinated. The rate of Guillain-Barré syndrome in 2009 was 10-fold lower than in 1976. Researchers estimate the 2009 vaccine may have caused 1 additional case of Guillain-Barré syndrome per million vaccinations, while the the vaccine prevented 200 to 520 deaths due to the flu.

What works: Local control

Although you hear a lot from the CDC and the rest of the federal government—not to mention the World Health Organization—about how to respond to the flu, the real decisions are often made by states and localities. “Everything is local,” says former CDC director David Sencer, MD. “The federal government can give guidance, but implementation has to be left to the local communities. Who are the key emergency workers to immunize, for instance? If you ask my daughter in Minneapolis, she’ll say it’s the snowplow driver. If you can’t move around the city, you can’t take care of sick kids.” The downside is that with states, cities, and even school districts formulating their own policies, you may hear conflicting advice.

Take-home lesson: To help sort things through, you can find helpful information at central clearinghouses: The federal government’s is at, and the CDC tweets updates at @CDCemergency. If you need more motivation to get your flu shot, read up on these 12 flu myths that are really true.


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