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6 Common Misconceptions about the Flu–and Flu Shots

The views expressed are those of the author and are not necessarily those of Scientific American.

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MALTA—Efforts to create a universal flu vaccine, one that would do away with the annual reformulations, is a hot topic these days in the infectious disease community. But in the bigger picture of reducing flu transmission—and reducing the thousands of deaths it causes in the U.S. each year—there is a big leap forward that could be taken with already available tools. Researchers and public health officials these days agree that a vast improvement now would simply involve inducing more people to get existing annual flu shots.

Popular confusion about the influenza vaccine—how effective and how safe it is—is part of a broader misunderstanding about the flu in general, noted a panel of doctors and health workers on Tuesday at the European Scientific Working Group on Influenza’s annual conference in Malta.

Here are six common misconceptions about the flu, according to the panel—supported by the latest research:

1. Influenza? No big deal, it’s just the flu.

“We are always underestimating the disease,” Roman Prymula, of the University Hospital Hradec Kralove in the Czech Republic, said on Tuesday. Although a minority of the adult population comes down with the seasonal flu each year, he said, the number of deaths in which influenza plays a part is vastly underreported. By some estimates, he suggests, only about a quarter of deaths from the flu are reported as such—the remainder are often categorized as due to conditions such as cardiovascular complications. The U.S. Centers for Disease Control estimates that some 36,000 people die from the flu—or influenza-related causes—each year.

2. Me? I’m not in a high-risk group.

The seasonal flu is a particular threat to the elderly, whose immune systems are not always up to the task of fending off the infection—and who are more likely to have underlying medical conditions that make them more vulnerable. But the recent experience with the H1N1 2009 pandemic was a reminder that some strains of the flu can be more deadly for the otherwise healthy, who are in their prime—25 to 50 years old.

3. Flu shot? It’ll probably give me the flu.

“You can’t get it from an inactivated vaccine,” said Betty Voordouw, of the Medicines Evaluation Board in the Netherlands. She noted that it’s odd that patients typically accept that other vaccines will cause a slight fever, and even take that as a sign that they are working correctly with the immune system. But when it comes to the flu shot, at any sign of sickness, many people assume the shot has given them the full-blown flu.

It’s especially tricky in the real world, as flu shots are usually given about the time respiratory and other infections are starting to spread, said Arnold Monto, of the University of Michigan. And, he noted, “We have a lot of other respiratory illnesses out there that look like the flu.” Many gastrointestinal viruses go masquerading as “the flu,” he said, because it “has become a polite way of saying, ‘I’ve got diarrhea,’ so we have this kind of confusion going on when you hear people say, ‘I got the flu in spite of the flu vaccine.’” As a health professional, he adds, that he and others “need to try harder to explain just what it is that we’re preventing.”

The most likely side effect of the flu shot? A sore arm, Monto said, which is reported in about 40 to 50 percent of people in controlled trials. And if you are getting a live attenuated vaccine, the next most likely side effect is a mild stuffy nose.

4. I got my flu shot last year, but I got the flu anyway—it probably doesn’t even have the right strains in it.

“In the past, we may have oversold how well the vaccine do work,” Monto said. “We have, as I categorize it, a good vaccine—not a great vaccine.” Previous studies, which were conducted largely among members of the U.S. military showed a 70 to 90 percent protection rate. But recent studies hint that the more standard rate is probably closer to 70 percent, Monto noted, adding that he would really like to see a more effective vaccine for young children and the elderly.

Today, there “is really a word wide surveillance system,” said Bruno Lina, of the University of Lyon. And even though the strains to put in the vaccine for the northern hemisphere’s flu season have to be selected in advance, in February, so far researchers have done a pretty good job of predicting correctly which strains will circulate some eight months later.

Take a cue from computer engineers, Lina said, adding: “When people buy antivirals for their computer, the computer says, ‘Bing! You have been protected.’ I wish vaccine manufacturers could prepare something like that.” The problem with any preventive measures, added Monto: “If you don’t get something, you don’t know that you’ve been exposed—and you don’t know that you’ve been protected.”

5. Adjuvants and other ingredients of the shot are dangerous.

In pure scientific logic, as Voordouw pointed out, “you can never say that anything is safe.” Adjuvants, which boost the immune response and thereby require less of the virus, have been controversial in the U.S., but not so much in Europe and beyond. Even with adjuvants, which also act as a preservative, “I think the benefits of adding an adjuvant to an influenza vaccine will far outweigh the risks,” she said.

It can be tough to accept an option that carries any risk at all, Lina said, especially in the U.S. where the public seems insistent at times on zero risk. That sort of logic, he notes, from a public health standpoint “is stupid behavior—because you’re dealing with disease, and you have to weigh the benefits and the risks.” And, he acknowledges, that can be a difficult exercise for people unaccustomed to very consciously accepting small amounts of risk for a much larger benefit—both to themselves and the people around them.

6. There’s no treatment for the flu, so I’ll just take some aspirin.

The flu is tough to treat not because we don’t have the right medicines (Tamiflu has been a successful antidote so far), but because it is actually a relatively short-lived illness. As miserable as it can be, most adults clear the infection on their own in five days. But because they often wait two to three days to see the doctor, and Tamiflu clears the virus in three days, some times it wouldn’t make much of a difference. But, as Lina points out, when you’re miserable with the flu, even a one-day reduction in the sickness is a huge relief.

Of course, for people in high-risk groups, early treatment reduces the need for intensive care, along with overall mortality. In places such as nursing homes, where an outbreak of the seasonal H3N2 flu can kill as much as 10 percent of the population, examples in France have shown that even giving Tamiflu as prophylaxis has been shown to cut off the epidemic. But for normal circumstances, these antivirals should be saved for such pandemics—for when we don’t have other means of prevention. For the seasonal flu, though, there just happens to be a relatively safe and pretty effective way of avoiding it already, which is just a quick needle jab away at your local pharmacy, workplace or doctor’s office.


Katherine Harmon Courage About the Author: Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. lamorpa 9:34 am 09/13/2011

    Everything presented he is in direct contradiction of the research by Dr Jenny McCarthy. We all know the flu vaccine causes autijennymccarthysm.

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  2. 2. patmcgee 10:12 am 09/13/2011

    I’d like to see references to the studies that Dr. Monto refers to claiming 70% protection. The two times I’ve googled for such, I’ve found stuff like this:
    Flu in elderly: Hospital admissions for flu or pneumonia: 0.7% for unvaccinated, 0.6% for vaccinated. Death from all causes: 1.6% for unvaccinated, 1.0% for vaccinated. Sample size 713,872 person-seasons over 10 years, 4599 hospitalizations for pneumonia or influenza. Subjects not matched, so differences in baseline health for the two subgroups cannot be ruled out. [N Engl J Med 2007; 357:1373-1381]

    If what I found is not representative, I’d sure like to know about it.

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  3. 3. unre9istered 11:18 am 09/13/2011

    To patmcgee: I’m guessing you’re seeing the difference between relative and absolute percentages. The lower numbers are the absolute percentages. The absolute percentages are 0.7% of unvaccinated people hospitalized for the flu vs 0.6% of vaccinated people, so the vaccine reduces your relative risk of hospitalization by 15% (0.6/0.7) (according to your data). The absolute percentages of dying from the flu are 1.6% for unvaccinated vs 1.0% for vaccinated, so the relative risk of dying from the flu is 62.5% (1.0/1.6) less for a vaccinated person. Your data doesn’t seem to disagree much with the article given the underreporting of flu deaths mentioned in the article. I suspect the difference in hospitalization numbers may be a matter of self selection, meaning that people who don’t get the vaccine may be more likely to tough it out at home rather than go to a hospital.

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  4. 4. ASHIK 11:27 am 09/13/2011

    It is hard to believe about 36000 people from country like U.S die each year by flu.

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  5. 5. eurotimbr 8:02 pm 09/13/2011

    to unre9istered: a reduction from a rate of 1.6 to 1.0 is 37.5%, not 62.5%

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  6. 6. patmcgee 8:12 pm 09/13/2011

    To Unre9istered: Thanks for your thoughtful comment. I want to quibble with it in a quest to understand, not to try to denigrate your comment. You may have phrased things in a way you didn’t quite intend or you may have slightly understood my comment; I can’t tell.

    You said “… the relative risk of dying _from the flu_ is 62.5%”. The part “from the flu” was not in the original. 62.5% more people who were unvaccinated died from _some_ cause, not just from the flu.

    You made a really good point about the self-selection effect, which I hadn’t thought about. Without matching subject pools, I don’t have a clue how to guess how much difference it might make.

    Given that, I don’t see the study I cited as supporting the 70% claim very well. I think it supports a claim of 15% somewhat better.

    Do you (or does anyone) know of a published meta-analysis of the effectiveness of flu vaccines? I haven’t been able to find one (in my admittedly paltry 45 minutes of googling.)

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  7. 7. donaldcarl 5:23 am 09/16/2011

    Dear Sirs: I am worried about the “scientific ob- jectivity” of Sci Am writers. I searched in vain for a reply to “comment” on vaccinations cited in the 9-11 issue, but it is not there. Did the drug companies forbid you to have one? If the drug and vaccine industry could inspire a little trust, they might be able to sell their wares. They make billions and spend millions in controling the press to sell more. There is autism, bribing congress, etc. You refuse to print my letter to tell the truth and they attack valid critics in media, movies, etc. They are part of a complex of pharmacological-psychiatry media-Asylum owners, to lock us aware ones up,for the goals of profits, control of our freedoms, and keeping us at govt expense. Why doesn’t S.A. print the truth and embrace science instead. Drug profits are sweet are they not? But losing our Constitutional liberties is bitter! Their products do as much harm as good. Expose this, please! Dr. D. Leavitt (See R.Bentall, R. Whit-aker, R.Wright, etc.)

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  8. 8. drrubin 4:38 pm 10/21/2011

    As a pediatrician and parent, it is difficult for me to understand why people would forego immunization and risk getting influenza. It is not a fun illness. Most everything in life is a balance of risk vs. benefit, and in my opinion, the very small risks associated with the flu vaccine pale in comparison to the risks associated with the virus itself, the most permanent of which is death! (

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  9. 9. FarScout 11:18 pm 10/11/2012

    I mostly agree with drrubin. But do you, Sir, agree that it should still be a person’s choice whether or not to be vaccinated?

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  10. 10. comefullcircle 2:31 am 01/27/2013

    I’d like to add a seventh misconception onto their list:
    “If you don’t get a flu vaccination, you’ll get the flu.”

    Big Pharma has a vested interest, to say the least, in pushing the vaccinations on the public – what better way to keep that money flowing in than to convince people that they need these vaccinations? You could not pay me enough money to be the recipient of a government-sponsored vaccination. One look into the Polio vaccination campaign of the 1950′s; and learning how the government reacted when it was discovered that those vaccines were contaminated with at least 40 viruses – the one called “SV40″ being of paramount concern – taught me that the state of my health was not at the top of their list. What was in position #1 on their list of “most important issues”? The Almighty Buck, of course. Think I’m crazy, or don’t know of what I speak? Think again, and educate yourself by reading a book called “Dr. Mary’s Monkey” – or better yet, simply insert the term “SV40″ in Google’s search box. Read more than one search return result, and then ask yourself: do they really have my best interests in mind when they are trying to coerce me and my family to receive these vaccinations? Don’t just blindly allow anyone to inject you with something unknown that “they” say is for your own good – use the brain you were born with, and apply some critical thinking.

    Oh, incidentally …. I have never gotten a flu vaccination, and I’ve NEVER had the flu.

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  11. 11. PaulJames 3:49 pm 10/4/2013

    I think you did a good job clearing up misconceptions about the Flu… We provide FREE Flu vaccinations to all our Associates and insurance members and understand even though influenza is much more severe than a cold, it is preventable by getting an annual flu shot. The vaccination also helps to not spread the virus to family members as well as others. So this year we put together a video for our associates to help lighten the mood around getting vaccinated… It is a parody on the Kung Fu Fighting Song… “Kung Flu Fighting” take a look:

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