December 14, 2019
Why Does the Flu Come Back Every Year?

Why Does the Flu Come Back Every Year?


‘The flu’ has become a slang term
that refers to almost any ailment where you juuuust don’t feel quite right. But influenza proper is a handful of specific
viruses that invade the respiratory lining, evade the immune system, and mutate at a rate
that even the world’s most brilliant doctors, scientists, and health organizations struggle
to keep up with. So what is Influenza exactly, and why does it always seem
to be one step ahead of us? Some of the confusion around the term ‘flu’
may stem back to the word’s roots: “Influenza” is an Italian word that just means,  ‘influence.’ Because, back 500 years ago, people
didn’t know about germs then. They thought if you got this disease, you
were under the influence, perhaps of the stars or something else. My name is David Morens. I’m a medical doctor and an epidemiologist,
and a virologist, and a historian, at the National Institutes of Health, and an officer
in the United States Public Health Service, and I’m here today to talk about one of my
favorite subjects: influenza. Influenza presents with such iconic symptoms that many other diseases are classified by
their similarity to it. Tell your doctor you’re experiencing ‘flu-like
symptoms,’ and they’ll know exactly what you mean: coughing, fever, head and muscle
aches, fatigue, and well, just general “malaise…” …which kind of means just feeling really
bad. Anybody who’s ever had flu knows what it is. But while many illnesses are similar to influenza,
there’s only one True Flu. Well, four, actually… and trying to put
a finger on its countless variations and mutations is actually where influenza starts to get
the better of us. Depending on how you cut the cake, there are
billions and trillions and zillions of different types of influenza. But to start, we categorize them into four
categories: Influenza A, B, C, and D. The ones we’re most interested in because they
affect humans every year are A and B. C also infects humans, but it’s pretty much a minor
disease that affects children, and D is mostly an animal disease that people generally don’t
get, or at least they don’t get symptoms from it. Influenza A, B, and C for the kiddos, start
by entering your upper respiratory tract, either when you breathe contaminated air,
or touch your nose and mouth after coming into contact with the virus. The only cells it really infects are what
we call respiratory epithelial cells, a one-cell layer of cells that kind of protect the breathing
tubes and the lungs, all the way down to the bottom, where we have air sacs. Those lining cells are the ones that get infected. Once they reach your respiratory lining, the
viruses attach to a specific kind of cell receptor, called sialic acid. If you could see them up close, they’d look
like branches of trees. They stick out and they go in all different
directions. They kind of capture things, and by binding
to it, it can be dragged inside the cell, where it causes the infection. The influenza virus then makes its way through
your respiratory passages, in rare cases, reaching all the way to the bottom of the
lungs, and leading to severe pneumonia. All this suspicious activity would normally
cause your body to launch an immune response. And usually, it tries to. But this is complicated by the fact that the
virus and the immune cells coming to the rescue are separated by that epithelial barrier. That’s one of the reasons it makes it hard
to develop strong immunity to flu, and to raise strong immunity by using a flu vaccine. And as if that weren’t enough, even if you
are able to mount a defense of some sort against the virus, influenza has already invented
several thousand more versions of itself, before you can blink an eye. Influenza viruses are not stable things. They’re always moving and changing, day-to-day,
hour-to-hour, minute-to-minute. Mutation is all they can do. There is no state of their existence in human
beings that is not constantly mutating. This is because of a machinery in their RNA
that causes consistent errors in gene replication. But, unlike for humans, these ‘errors’
actually works to the virus’s advantage. They’re good errors that help them to survive. Even in your own body, if you are infected
with an influenza virus today, you’re not going to be infected by one virus. You’re going to be infected by let us say
1,000 or 10,000 viruses. And it’s this rapid-fire mutation that makes
whipping up a vaccine for this set of viruses a pretty tall order. Each year, researchers from the World Health
Organization and around the world develop one vaccine for the Northern Hemisphere, and
one for the Southern. These vaccines are released six months apart,
to coincide with winter’s ‘flu season’ in each area. Their recipe is slightly different each time,
and can be tailored for specific types of patients, like the elderly. The current vaccines have four viruses: two
influenza A, and two influenza B. And it may or may not work. Because in the meantime, the viruses circulating
around the world may have mutated to the point where your best guess vaccine is worthless. So, the scientists have to guess now, what
vaccine they’re going to need six months from now. It’s like looking into a crystal ball. And in addition to this seasonal cycle, every
three decades or so, the stakes ramp up, and the disease is dramatically more hostile,
causing a pandemic. The years we have a pandemic, as many as 50%
or 60% of all people might be infected within a year. That virus causing a pandemic can come at
any time of year. Eventually, we don’t call it a pandemic anymore
– we call it a seasonal virus. But all over the world, research continues
on influenza, and the hope of a universal vaccine could be in sight. A lot of scientists, including NIH and CDC,
are working very hard on this. Every year, all over the world, thousands
of influenza viruses are being taken from patients, and sequenced. This gives an idea about what directions the
evolution of this virus is going. By learning how the body can successfully
control influenza, we have a better idea how we can mimic that with a vaccine. But in the meantime… Don’t walk, run and get your flu shot, every
year.

89 thoughts on “Why Does the Flu Come Back Every Year?

  1. Quite intriguing how The Flu specifically targets humans and don’t affect any other life form. Nature is always trying to kill you.

  2. Someone should make a poison whose antidote can only be received via flu shot, in order to eliminate the anti-vaxxers…

    …oh wait.

  3. I get a flu shot every year but watching this video made me realize something…

    If the virus mutates so rapidly and randomly and a flu shot can only protect you against a very small number of these mutations (sometimes some guess work is done)…then what's the point of doing it?

    You will only be protected against those specific ones and interacting with those specific mutations in real life (out of thousands of possible variations) is pretty much like finding a needle in a hay stack.

  4. all doctors have to do is swipe themselves with a sample of the flu, then go
    out to a bar. after that, wait for clients.

  5. Another reason the Flu is so bad is because people go to Work, School or Shopping and share Virus around, My 18 month old son just got over Influenza A and Gastroenteritis in about a week his grandmother caught it from him and has been sick the last 3 weeks and is now getting better I didn't get sick at all….

    HOOORAY FOR ME…. but I have not had a Flu in about 5 years the next one I catch is gona SMASH ME.

  6. I’m pro vaccination(because I’m not mentally challenged), but I stopped getting my flu shot ~10 years after having a terrible flu two times in one year after getting the flu shot. I have not had any major flu symptoms since then. I’m not conspiring on anything, but the flu shot is one thing I genuinely feel like is pushed very hard, with little results proving it works as advertised(opinion).

  7. We definitely need ai working on this, we have plenty of data to feed it and the problem seems too difficult for humans to deal with quickly enough to stop the disease.

  8. Schools will allow transgenders to come in and talk to your young children, but they wont let young children in those same schools unless they are injected with toxins.

  9. Sometimes I still don't understand why people don't trust vaccines when you have all this proof, knowledge. Pretty much why do people distrust people who spent years learning for them to just say "Nah, I don't believe that is how it works" with no knowledge of the matter

  10. The flu virus is present all year round. The reason it 'comes back' every year is because people stay inside more in the winter, making it easy to spread. This is why flu shots are pushed so heavily in areas that experience 'real' winters…

  11. So why the hell do we get a flu shot then ??? it does nothing……..if you want to attack the flu then why aren't we using an inhaler to attack it ?????

  12. One reason women get sick less.
    Is because of thin layer of Brown fat .
    Even the skinny chicks have it. .
    Holds to ant bodies.

    For men I suddgest vibrating your throat getting more blood and cells to areas to where those infections start.
    If already sick .sense Women get sick less i would suggest taking soy until you get better. Consider any feminization a temporary side affect

  13. Reason women get sick less maybe because of a layer of brown fat storing more antibodies. Even the skinny chicks have it.
    For men I would suggest vibrating your throat sending more blood and imunity cells to eara's where infections start.
    And if already sick sense Women are better fighting cold&Flu I suddgest taking soy and consider hormonal changes a temporary side affect

  14. Propaganda!
    And, you never answered the question.
    I will answer it.
    The flu season starts with people getting their vaccine shot and then traveling to their families and friends homes for " Thanksgiving " .
    It is like what we called " the crud " when I was in bootcamp.
    People traveling in from all over and bringing their various " germs " with them.
    Guy is wearing a uniform with RIBBONS? What did he do to receive his MEDALS AND RIBBONS?
    NOTHING!
    Have a wonderful flu season.

  15. I discovered how to avoid getting the flu for over 25 years now. Haven't been sick since. I have never had a flu shot! Go figure. What are the odds that this method works so well? I worked for over a decade in small office with several other employees who every year went and got the flu vaccination. Like clockwork they all got sick with the flu. I was the only one in the office who didn't get the flu. I do two different things to prevent me from getting the flu. Simple but highly effective.

  16. I've never had a flu shot, or the flu. I do, however, have chronic sinusitus, and I think my sinuses are BOSS, and when the flu tries to invade its territory, my sinuses are like, "Oh NO YOU DIDN'T". 😂

  17. The flu will never over until big pharma stops mutating the virus and stop cloud seeding via the help of the CIA and the airlines. Wake up sheeple!

  18. Get this stupid transgender shit off your insignia . You dont represent America on veterans day but you represent people with mental illness who want to cut their kids dicks off. Pathetic. Get your stupid political beliefs off your page and focus on science.

  19. I THINK ITS THE HIGH SODIUM IN OUR DIET THAT WEAKENS OUR IMMUNE SYSTEM DEPLETION OF VITAMIN D ALONG WITH WITH CHANGE OF SEASON. SALT CAUSES THE DEPLETION OF VITAMIN D CAUSES OSTEOPOROSIS. PEOPLE GET SICK RIGHT AFTER THANKSGIVING WHY? You can say people gathering spreading the virus or high intake of salt do to thanksgiving dinner causingvthe depletion of vitamin d as well as the shorten days.

    Let thy Food be thy medicine and thy medicine be thy food- Hippocrates

    Question Everything- Socrates

  20. Why is it every time I get a flu shot within 24 hours I get very sick, but when I don't get a flu shot, I never get more than the mildest case of the flu, if I get sick at all?

  21. I just got the over 65 flu shot which is supposed to be more potent, but I actually don't remember when I last had the flu, but I do remember the two times I've had pneumonia and I had that supposed shot too…let's talk about the Black Death which by the way has again shown up recently in China, but they don't want to scare people so they don't talk about it….

  22. Humans are smart but we'll never be smart enough to outsmart nature. The original vaccine for the flu is in nature. Not in a lab.work with nature not against it. There are thousands of plants that are antiviral antimicrobial antibacterial to include flu fighting/aborting and their different chemistries are enough to prevent or abort a flu along with nutritious food. Not saying don't get vaccinated but we shouldn't rely solely on vaccines to not get sick. Sometimes scientists don't get it right as we saw about 2 years ago. Sometimes people just don't respond well to the vaccine itself.that was my first time ever getting the flu but i also had generally already been sick that whole year i'm 28 now. Hope I never get it (get sick from it anyway) again.

  23. Loved the video. Just wished the audio was a bit louder so I can hear it while I am listening to it on the trian with my headphones on.

  24. Nice to be told the truth. The media must be hyping vaccines for the drug companies. Knowledge about flu vaccines could put a stop to them and one less poison for humans to be burdened with.

  25. 0:44 If you are a doctor and you wanna talk about influenza, just talk about it and wear like a doctor no need to promote your self and your CV !! no one is hiring here.

  26. No 1 DONT get the flu shot!! I got deathly sick the two times I tried it.
    Then I got smart and read the ingredients in vaccines. Pure poison!!
    Plus I wash my hands every single time I come in the house, keep my hands out of my mouth and I haven’t got sick at all in 15 years other than the 2 times I had the stupid vaccine.

  27. thats weird.. when i got the flu or anyone ever.. it had zero to do with lungs.. and everything to do with diarrhea… puking.. and all around feeling like death.. doctor always said flu.. and thats what we underatand it to be in the u.p. sounds like this flu is more like the comon cold… which can get kinda nasty yes.. but nothing compaired to the flu.. so since we alrdy have colds.. ammonia.. what was the sickness we called flu as kids?

  28. Viruses live in the upper atmosphere and float from continent to continent via the jet stream…all the digging in Antarctic has released a slew of new virulent germs and virus which have the propensity to wipe out all life on earth….solution: spray the sky with chemicals. After our nuclear explosions in space in the 60's Operation Fishbowl/Starfish Prime…has allowed interstellar microbes into our biosphere…a containment operation has been under way for years to reduce its effect on earths life….mainly our oceans.

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