What’s the deal with the flu?

Today we’re talking about the influenza virus, which we mostly just call the flu. It’s in the news, and based on the questions my mom was asking me recently about flu vaccines and my dad wanting to talk about NY Governor Cuomo’s recent declaration of a state of emergency due to the flu (Hi, Mom! Hi, Dad!), and since it’s alllllll over the news, I thought it was time to have a conversation about flu here.

Important reminder: I am not a medical doctor, and I am not YOUR medical doctor. I am a professional scientist who has spent years studying infection and who spends a lot of time talking to medical doctors.

Influenza_virusEM of influenza virus
LEFT: Cartoon picture of the influenza virus, courtesy of the National Institute of Allergy and Infectious Disease, which posted it on Wikimedia Commons. RIGHT: a picture taken of influenza with a transmission electron microscope, courtesy of the CDC, which posted it on Wikimedia Commons.

I’ll break with my preferred formatting today to try to get at what people want to know, regardless of good or bad reporting, but I’ll still list some sources for not-quite-perfect news stories and some trustworthy sources of info. Also, I had the H1N1 “swine” flu in 2009 and it was pretty awful, so I want to be a bit more personal and practical when I talk about this! (I had a meeting when I was done with the worst of the infection and was trying to come back to work, and the person in the office next door later commented to the person I met with that he was thinking he needed to get ready to call 911.)

News stories and such about the flu:
Boston Globe: With Boston undergoing a flu emergency, guess who’s not getting the flu shot? A lot of us
NPR: Phooey on flu
(Also, check out my Twitter feed. This week I am retweeting flu-related stuff.)

Learn more:
From the World Health Organization
From the United States government center for flu information
The Centers for Disease Control and Prevention Flu Shot page
From the American Experience hour-long documentary on influenza, from PBS. (I love PBS! And while I know a lot about the flu, I learned some really interesting stuff from this show.)

Why this is news: The flu is making a lot of people in the US sick right now, so…it’s a good opportunity to talk about it!

What I want to clear up: Okay, so, influenza? We talk about it like it’s just some thing, right? It’s in our advertising and in our TV shows: oh, sure, it’s winter – it’s cold and flu season again! When you’re sick, you often tell people “Yeah, I have the flu.” (…even though most of the time it’s another virus, or a bacterial infection!)

Influenza is the only thing that’s actually “the flu,” so let’s talk about it specifically. It’s a virus: a small set of instructions that are wrapped up in protein. The picture above is pretty helpful: you can think of the flu as some stuff inside of a little ball with other stuff sticking up off of the outside, and while that’s not the most accurate way we can describe it, it’s quite good enough for most of us.

What do the H and the N mean?
The H is short for hemagglutinin – one of the kinds of bits of stuff that sticks up from the surface of the flu coat. The N is short for neuraminidase – the other major kind of bit of stuff that sticks up from the flu coat.

These are important because your body recognizes some invading germs based on what sticks up from them. The reason you hear H1N1 or H3N2 on the news is that we scientists use these abbreviations as a code for what the outsides of the flu look like. And that’s what goes in to designing a vaccine!

Ruby Hirose
Dr. Ruby Hirose, a scientist who studied vaccines – shown here working at a crowded lab bench. Not flu vaccines, but since we’re talking about vaccine biology, why not? Click the picture for more information about Dr. Hirose!

Why is there a new vaccine every year? Two main reasons: the “flavor” of flu that’s most common changes from year to year, and the details of that flavor change from year to year. In a nutshell, the people who make vaccines try to figure out which flavor will be the one (or which few flavors will be the ones) to bust out into public in a big way during the upcoming flu season. (Because it takes time to grow the vaccines, they have to be designed weeks or months in advance!)

An example: Let’s say that the H is a code for a flavor of ice cream, and the N is a code for a flavor of topping. In the primary place where flu lives (this is called the “reservoir” – and often, germ reservoirs are other living things that don’t get sick when they’re infected), there are a bunch of flavors of ice cream: vanilla, chocolate, mint, strawberry, etc. There are also a bunch of toppings: Oreos, peanuts, cherries. So scientists spend a lot of time trying to understand which flavor will be the one that gets out.

Some years, a new flavor comes out of the reservoir (or instructions get swapped for other reasons and an “old” virus now has a “new” flavor) – this is called antigenic shift. All of a sudden, a big change = a shift in the antigen, which is the formal word for a thing that makes your immune system respond.

Antigenic drift vs shift
A cartoon of antigenic drift vs. antigenic shift, courtesy of the USDA, via Wikimedia Commons.

Happily, not all flavors can leave the reservoir. This is kind of like reference books at the library. Biologically, it turns out that some variations of the flu can’t survive inside people! Which I think is way cool, and it’s one reason I study how germs and hosts interact.

Okay, so sometimes new flavors, or retro flavors, get out. (Also very cool, if a bit scarier: we think that the recent H1N1 flu is actually a reappearance of or otherwise related to the 1918 “Spanish” flu. I’m not sure I agree 100% with that report, for what it’s worth, but I haven’t had a chance to look into that yet. When I was in graduate school, though, I do remember learning that flu pandemics – when the flu gets really bad all over the world – happen every few decades. I don’t remember if that was thought to predate 1918 or not; World War I was kind of a big thing about then, too.)

But remember I said that the details change? This is called antigenic drift: it’s a smaller change, but it matters. Keeping to the flavors idea: this is basically like different kinds of vanilla ice cream. Sometimes you get vanilla bean, or French vanilla, or pure vanilla flavor, or artificial vanilla flavor – all vanilla, but you can totally taste differences! So scientists *also* try to figure out what subtle changes to the flavor are likely to be out in the world, to make sure what’s in the vaccine gets your body ready for the right invader. Add in the difference between a roasted peanut, a roasted salted peanut, a honey roasted peanut, and whether the peanuts are chopped or whole, and you can imagine that there’s a lot to consider when designing a vaccine.

There is a lot of similarity between vaccine design and any other math-based prediction where weird things can happen. Like filling out NCAA basketball playoff brackets or betting on who’s going to win the Superbowl. Many (most?) people don’t pick the right winner, even though a lot of people know all about the players and teams and stats and more. And sometimes total newbies pick the winners, somehow!

Should I get vaccinated? YES, PLEASE. I mean, check with your doctor, if you’re worried, or if you have some medical condition. But in general, vaccines are an amazing tool we have to fight disease. I get that people are concerned about the safety of vaccines – trust me, I’ve had enough of them in my life to feel that way, too – but here’s the thing: if the flu vaccine were truly that unsafe, then literally MILLIONS of people around the world would get hurt by the vaccines on a regular basis. Which…just common knowledge should help us all feel better that that’s not true. (Note: I do not blindly endorse public health agencies and certainly not for-profit manufacturers of vaccines. You shouldn’t blindly trust anyone – not even me! – but…that doesn’t mean that we can’t use basic logic to debunk a lot of conspiracy theories.)

Dr. Brainiac reminds you: some insurers and employers vaccinate people for free – it’s worth the time to see if you are eligible. Here in the US, a lot of the drug stores (Walgreens, RiteAid, CVS) also offer flu vaccines, and although these can be a little more expensive, it’s worth investing $10-$30 to make sure you don’t get sick. “Having the flu” is something we take for granted, but remember: influenza kills. There is no reason to panic, but why not protect yourself? Minor Downton Abbey season 2 spoiler: yeah, yeah, they ramped up the drama…but the 1918 flu storyline was not exaggerating.

…are you serious that I could die? It’s just the flu! I’m afraid so. Influenza kills something like 250,000-500,000 people per year around the world, and an estimated 36,000 people in the US each year. MOSTLY, we expect people who die from the flu to be very old or very young, since their immune systems aren’t as strong as teens and adults. Sometimes, though, there are flavors of flu that kill mostly people in their 20s and 30s. Like that infamous 1918 flu.

But won’t I just get the flu from the vaccine? No.

Are you sure? Yes.

Let’s talk this part out: the influenza vaccines that are distributed in the United States are mostly dead virus bits. I’m not able to comment on what vaccine makers actually do to kill their viruses as they prepare vaccines, but based on techniques I’ve used in the lab, it’s not super different from the idea of using fire or a food processor to turn bread into bread crumbs. You can still recognize breadcrumbs as the same basic stuff as bread, but it’s not exactly normal to use breadcrumbs to make a sandwich. A vaccine is just a bit of stuff that is put into your body so that your own immune system does its amazing work and develops antibodies to the stuff in question – for flu, your body will probably make antibodies that recognize the H and N flavors that the vaccine designers picked, for instance.

From what we know, it can take from one to two weeks for your body to go through the entire process of figuring out what the “best” antibodies it can make are, making enough of them to neutralize invaders, and making special cells whose job it is to remember what the invaders looked like. If you have those special cells floating around your body and then someone sneezes on you (eeewww) and you breathe flu bits into your body? Those cells become active and get your body to ramp up production of those antibodies, and the antibodies take out the flu, and you don’t get sick. What’s even more awesome is that, to the best of my understanding, those special cells will stick around for pretty much all of your life!

Vaccines and antibodies are pretty amazing. (Clearly, since we still have to make new flu vaccines every year, so are flu viruses. Sigh.)

If you feel yucky after getting inoculated? Your body may just be dealing with stuff and wasn’t healthy enough to take on the vaccine in the first place. You may also have gotten unlucky and had a problem, but again: if there were really a high probability of getting the flu from the vaccine, thousands or hundreds of thousands of people would get the flu from the vaccine. Or you may have a rare allergy or sensitivity and you’re actually reacting to the egg that was used to grow the vaccine.

But I can still get the flu even if I get a vaccine, right? Sadly, yes. Sometimes we have every reason to think that chocolate will be this year’s flavor, and it’s actually blood orange. Sometimes we figure out that it will be vanilla, but between the time we start our factories up making vaccines and the time you get the vaccine, the flu has become vanilla bean. When I got the 2009 H1N1 flu, since that kind of caught people by surprise, my doctors still had me get the “normal” flu vaccine, to keep me from getting another flavor of the flu.

Vaccination US Navy
Picture courtesy of the United States Navy, via Wikimedia Commons

What if I don’t like needles, like the woman in the Boston Globe story? Oh, yeah, I get this: I hate needles. HATE THEM. Like, have nearly passed out multiple times from getting injections or getting blood drawn, partly because of panic. But I get my flu shot every year. If you need me to encourage you, email me or leave a comment. Bribe yourself. Get a friend to go with you. Don’t look, and talk about something else the whole time. Again: I had the H1N1 flu and it sucked. Getting the vaccine is soooo much easier!

What about the woman who said that she wanted to take a natural approach, and not put something in her body? A vaccine, it turns out, is not actually all that unnatural! Vaccines are just getting your body to do what it would normally do when invaded by a germ. Getting a vaccine is no more unnatural than, oh, taking a Tums when you ate too much of the wrong food. Or taking a laxative, or a sleeping pill – especially melatonin. (Eventually, we’ll talk more here about the argument that “natural” is superior, and how often “natural” is a misleading label. But today we’ll stick to flu.)

Photo of a public health service advertisement from the 1918 influenza pandemic. Text reads: “Coughs and Sneezes Spread Diseases”, “As dangerous as poison gas shells”, “Spread of Spanish Influenza menaces our war production”

Final thoughts: Regardless of your vaccination status, there are some easy things we can all do to minimize the chances that we pass infections to each other.

If you cough or sneeze, cover your mouth and nose with a tissue or cloth. Wash your hands regularly, and before you touch your eyes, nose, or mouth (those are “vulnerable” points where germs can sometimes get into your body more easily). Don’t worry about using antibiotic soap – regular soap is just as good for you, especially if you scrub carefully, because soap causes a lot of living things that are cells to pop open and can mess with the protein coats of some viruses. Plus, scrubbing? Helps to physically dislodge invaders from surfaces. During dry weather, consider using a hand lotion. If you wash too much or get dried skin, you can have small open wounds which, you guessed it, can make it easier for germs to get in.

If you must use sanitizers, try using high-percentage alcohol hand sanitizers (the most famous brand is Purell). Alcohol, like soap, basically just busts stuff open. Use bleach carefully to sterilize hard surfaces. I don’t know if personal UV cleaning gadgets have been reviewed for safety and efficiency, but *consumer-approved* UV is another reasonable way to clean stuff up. (I like these methods because they are not, like some antibiotics (as I’ve mentioned before), super likely to foster antibiotic resistance.)

If you get sick, try to minimize your time out and about. I know a lot of us work for places that don’t really let us have time off, but if you can get a friend to pick up your dry cleaning or deliver soup, that helps keep your germs from spreading. And just take care of yourself! Sleep and eat to help your body do its work of healing.

Stay healthy, everyone!

Small note: I had some problems with WordPress while writing this post. If you see errors (science, HTML, or prose), please let me know ASAP.


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