Articles, Blog

Why Does the Flu Come Back Every Year?

November 20, 2019

‘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


  • Reply Seeker November 19, 2019 at 3:27 pm

    Hi Seekers, thanks for watching! Want more episodes of SICK? Check out our playlist here:

  • Reply scott davis November 19, 2019 at 4:21 pm

    Did he say “ Don’t walk, run and get your flu shot

  • Reply Mariano Alippi November 19, 2019 at 4:24 pm

    Just a little hack

  • Reply zer0Bot November 19, 2019 at 4:25 pm

    I don't even walk to get that crap, enjoy your pneumonia

  • Reply santanaoutlaw November 19, 2019 at 4:35 pm

    The flu comes back because medicine is a quadrillion dollar industry

  • Reply Shashank November 19, 2019 at 4:54 pm

    I had influence 3 week ago, now i m ok.

  • Reply Mohan Arvind K November 19, 2019 at 5:02 pm

    I thought he was going to sneeze ! @ 3:12

  • Reply Matt Helfer November 19, 2019 at 5:13 pm

    Does that officer have a shaving profile?

  • Reply Mariano Alippi November 19, 2019 at 5:15 pm

  • Reply Mariano Alippi November 19, 2019 at 5:18 pm

  • Reply Johnny Walker November 19, 2019 at 5:32 pm

    He needs more credentials

  • Reply pincode0000 November 19, 2019 at 5:40 pm

    Funny, i just thought about this the other day. Thanks for the video.

  • Reply Kargadan November 19, 2019 at 6:02 pm

    hmm wonder if we could program a computer virus that intentionally makes errors/changes to never be fully deletable… thank you influenza/Seeker… gets back to programming

  • Reply Texas Viking November 19, 2019 at 6:08 pm

    Call me crazy idc all I know is the first time I ever got a flu shot one week later I get the flu for the first time ever.

  • Reply Jared I November 19, 2019 at 6:28 pm

    No original comments 🤦‍♂️

  • Reply Mariano Alippi November 19, 2019 at 6:32 pm

  • Reply Parminder Jaura November 19, 2019 at 6:37 pm

    It's like call of duty, comes out every year worse and worse.

  • Reply Mariano Alippi November 19, 2019 at 6:49 pm

  • Reply Mariano Alippi November 19, 2019 at 6:50 pm

  • Reply Bjorn Vollheim November 19, 2019 at 6:50 pm

    He made all the good argumentes why a flu vaccine don't work,and ending with ; Take your flu vaccine???

  • Reply sirdeadlock November 19, 2019 at 6:51 pm

    Once again, not making it clear that bolstering your immune system with a flu shot does not stop you from getting sick by and being contagious with the flu.

  • Reply hellcat1988 November 19, 2019 at 6:51 pm

    Meanwhile I'm sitting here taking my genetically inherited immunity to influenza for granted…

  • Reply FreedomWorkshop November 19, 2019 at 6:53 pm

    Anyone I ever saw getting a "vaccine" got the flu real bad. Everyone I know that refuses to get them is rarely sick. It's a scam.

  • Reply Mariano Alippi November 19, 2019 at 6:58 pm

  • Reply Mariano Alippi November 19, 2019 at 6:59 pm

  • Reply Mariano Alippi November 19, 2019 at 7:02 pm

  • Reply Mariano Alippi November 19, 2019 at 7:02 pm

  • Reply Mariano Alippi November 19, 2019 at 7:03 pm

  • Reply Mariano Alippi November 19, 2019 at 7:05 pm

    Gentalman contiuos doing commerce of the good will round the world

  • Reply Mariano Alippi November 19, 2019 at 7:07 pm

  • Reply Mariano Alippi November 19, 2019 at 7:08 pm

  • Reply D_92 November 19, 2019 at 7:14 pm

    I'm 27 and have never had the flu before even when i've been around sick people. Is something wrong with me haha.. ;/

  • Reply Mariano Alippi November 19, 2019 at 7:16 pm

  • Reply Mariano Alippi November 19, 2019 at 7:21 pm

    It is beautiful but in this case he is drugged, read between lines

  • Reply Mariano Alippi November 19, 2019 at 7:32 pm

    Letal virus

  • Reply Mariano Alippi November 19, 2019 at 7:33 pm

    Letal virus

  • Reply Mariano Alippi November 19, 2019 at 7:34 pm

    Good hack

  • Reply Mariano Alippi November 19, 2019 at 7:35 pm

    Good hack

  • Reply Mariano Alippi November 19, 2019 at 7:38 pm

    Medicine true love with sure secure, you have to be sure to be secure, with Strong Western Tradition, stronng cultural identity

  • Reply Samuel Feynman Tribute page November 19, 2019 at 8:03 pm

    I have the flu as I watch. Did not make me feel better.

  • Reply Mariano Alippi November 19, 2019 at 8:24 pm

    if you completely close the commerce, even the local internal commerce captured by Nationalist Populists Mafias, this can happen to any society

  • Reply Mariano Alippi November 19, 2019 at 8:27 pm

    Sure secure societies without crisis

  • Reply Naughty Nookie November 19, 2019 at 8:30 pm

    Stop vaccination! my kids never vaccinate and never have flu!

  • Reply Mariano Alippi November 19, 2019 at 8:44 pm

    This is not fiction at all, masive use of drugs by the Nationalist, both right and left, Facists both right and left, Populists both right and left centralized Mafias, social descompensation with massive use of drugs

  • Reply sdfkjgh November 19, 2019 at 8:44 pm

  • Reply Mariano Alippi November 19, 2019 at 8:46 pm

  • Reply Enrico Lucarelli November 19, 2019 at 8:50 pm

    But… why are we much more prone to get an influenza if it is cold? In summer we are basically out of danger. I have newer found a llegar explanation for that.

  • Reply Mariano Alippi November 19, 2019 at 8:59 pm

    He died in Venezuela due to masive drug abuse, so i think is much better a piano piano se va lontano

  • Reply Mariano Alippi November 19, 2019 at 9:08 pm

  • Reply Mariano Alippi November 19, 2019 at 9:21 pm

    They are doing it right now,

  • Reply George Washington November 19, 2019 at 9:34 pm

    Why Does the Flu Come Back few times a Year?

  • Reply Mariano Alippi November 19, 2019 at 9:36 pm

  • Reply Solomon Villagomez November 19, 2019 at 10:10 pm

    Where is Trace?

  • Reply Jun Rosales November 19, 2019 at 10:24 pm

    So, are influenza living creatures? Meaning, do they consciously or unconsciously evolve or mutate? Do they live with a purpose?

  • Reply olive4naito November 19, 2019 at 10:32 pm

    Remember it isn't always the flu. Flu vaccines are ineffective against the common cold and target only one strain if the virus. People are starting to forget about the common cold. I remember as a child how my doctor never recommend the flu shot because the chance of contracting the flu was minimal compared to the common cold.

  • Reply Mariano Alippi November 19, 2019 at 11:14 pm

  • Reply Zi_ogo November 19, 2019 at 11:27 pm

    4:00 what programme was that??

  • Reply yqa free November 19, 2019 at 11:40 pm

    I call this what it is.
    Absolute propaganda BS!

  • Reply Rusty Shackleford November 20, 2019 at 12:00 am

    How long have humans been suffering from the flu? Shouldn’t we have gotten all of them by now thus building immunity and passing it on to the next generations?

  • Reply Philosophical Harmonics November 20, 2019 at 12:02 am

    I've never gotten a flu shot in my life and I very rarely get the flu and if I do I recover within days. I'm not anti-vac but I see no logistical benefit to it at the same time.

  • Reply reality check November 20, 2019 at 12:13 am

    The Flu is like Trump, it just wont go away.

  • Reply Reverend Saltine November 20, 2019 at 12:20 am

    Lying bstrd from CDC states: flu shots don't do sht. THEN he tells us to "RUN" to get said flu shots. Jon Rappoport is right (look him up).

  • Reply miss misanthropist November 20, 2019 at 1:00 am

    thanks mom for not vaccinating me and making me put up with this bullshit every goddamn year

  • Reply kurt bennett November 20, 2019 at 1:04 am

    It keeps coming back because you keep making vaccines that in the end stop working. The body's natural vaccine is the best on the market. Create your own and you won't get the flue very often trust me.

  • Reply Brandon Piperjack November 20, 2019 at 1:20 am

    Soo the flu is mutating soo much that a flu shot is pretty much just a crapshoot?? But at the end of the video we are told to get our flu shots every year?

  • Reply Spaced Out November 20, 2019 at 1:21 am

    Why some viruses dont cross contaminate between species?

  • Reply Blitznstitch2 November 20, 2019 at 2:00 am

    David morens is life goals

  • Reply Wickedjr Reads November 20, 2019 at 2:09 am

    Tells us why the flu shot is absolutely worthless because it's like looking into a crystal ball then says run, don't walk, to get your flu shot
    riiiight. I'm not anti-vaccine, very pro-vaccine but the flu shot seems worthless. Every time I got it in the past, bamn got the flu, don't get the shot, usually don't get it. Though I have it now. Damn flu.

  • Reply Everything Science November 20, 2019 at 2:23 am

    "This video is so we'll at explaining the flu. Props to the seeker channel for making this video BRILLIANT"

  • Reply Pratwurscht Gulasch November 20, 2019 at 2:35 am

    1 minute in, still explaining what the flu is. i didn't come here to learn for the millionth time what the flu is 😛

  • Reply gh hg November 20, 2019 at 2:45 am

    Audio too low to boost above background noise

  • Reply DragonSheep November 20, 2019 at 3:18 am

    That thumbnail looks sick

  • Reply Kuhoo Not Kuhu November 20, 2019 at 4:23 am

    The audio engineer should have known better

  • Reply Pretty Boy Pete. November 20, 2019 at 4:24 am

    He says get the flu shot. No thanks

  • Reply Dankman9 November 20, 2019 at 5:06 am

    "The flu shot is likely worthless but run and go get one."

  • Reply Bradley Carls November 20, 2019 at 5:35 am

    You never answered the question why the flu is yearly….

  • Reply haloharry97 November 20, 2019 at 6:08 am

    I have never got the flu, I've never got a flu shot.

    But I get a cold every 2 months or so

  • Reply Austin Tavares November 20, 2019 at 6:25 am

    They should incorporate AI algorithms to help predict vaccines more accurately

  • Reply Ican FeeLIt November 20, 2019 at 6:34 am

    we make flu vaccines by injecting the virus in a chicken embryo the virus mutates to invade chicken embryos better than people we take that virus back and inject it in people, then in some individuals it doesnt die it mutates back into living on human hosts and that makes new strains it will never end

  • Reply Scolar Visari November 20, 2019 at 6:38 am

    Because they need to sell medication to treat its symptoms…. I bet it gets released every year seems weird it comes back every time of year…

  • Reply Mrbigolnuts November 20, 2019 at 6:49 am

    What a joke, I never take antibiotics, only ever sauna and gallons of lemon and honey when the flu starts, no need for drugs

  • Reply 3zEkie1 November 20, 2019 at 7:55 am


  • Reply 3zEkie1 November 20, 2019 at 8:03 am

    Somehow i feel that the question wasnt really answered …

  • Reply Bob Motster November 20, 2019 at 9:50 am

    Why do the planes fly so low over rural areas when the airport is a couple of miles away?

  • Reply Tony Elsom November 20, 2019 at 10:49 am

    Flu is flu..pharmaceutical bodies just give it another name each year. Welcome to capitalism sheeple..

  • Reply tommy aronson November 20, 2019 at 11:12 am

    This guy spent like a full minutes listing his useless titles

  • Reply yafiteli November 20, 2019 at 11:19 am

    That's a pretty sloppy looking uniform. What are all those ribbons? Are those hygiene awards?

  • Reply BDMA November 20, 2019 at 11:21 am

    Watching this while suffering from moderate flu. Nice.

  • Reply madhava gosa November 20, 2019 at 11:27 am

    certaintly the stakes is "rampping" up 4:47

  • Reply Derek Jacobs November 20, 2019 at 12:15 pm

    I haven't had a flu shot since I was a kid and haven't gotten sick in years even when im around someone that's sick

  • Reply Grant Goldberg November 20, 2019 at 12:18 pm

    Lack of vitamin d in the Winter. That's why it comes back.

  • Reply K!ngS!ze November 20, 2019 at 12:25 pm

    Never had the Flu ever…. and never had a Flu shot…

  • Reply MugenTJ November 20, 2019 at 1:27 pm

    May or may not work. I will not get a flu vaccine!

  • Reply waypasthadenough November 20, 2019 at 2:41 pm

    5 minutes and 45 seconds of telling us how useless the vaccine is then telling us to run and get one???? Huh?
    Big pharma needs your money.
    What are they not telling you?:

  • Reply Eric Tyler Dés Phuong Xin November 20, 2019 at 3:10 pm

    PLEASE JUST LET THE WOMAN NARRATE THE ENTIRE THING NEXT TIME, the man has a muffled voice that is so unpleasurable to listen to

  • Reply Joe T November 20, 2019 at 3:54 pm

    1 mandatory washing of hands. Use scented soaps to be able to notice.

    2 mandatory quarantine of person with flu in an isolated room. Sort of like detention in school.

    3 mandatory entrance door disinfectant in public places. Sort of how food warehouses work.

    4 mandatory face mask to those sick.

    Why people rely on "vaccine" is stupidity from all aspects of logic and common sense 😂💩😄

  • Reply Joanne Venere November 20, 2019 at 5:34 pm

    Thanks for releasing it every year and making it last even longer?

  • Reply ThePark 627 November 20, 2019 at 6:15 pm

    The Flu is just a systems check on the humans

  • Reply Rudy Amid November 20, 2019 at 7:50 pm

    So it's already known that it's difficult to figure out which flu viruses are circulating, yet "Run Don't Walk" to get your ineffective flu shot? Someone is making a ton of money with this scare tactic.

  • Reply Lori Lanili November 20, 2019 at 8:27 pm

    Understanding that, it appears to have studied politicians activities for success.

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