Should I Get A Flu Shot?

It is Influenza Season in the Northern Hemisphere. So, this is a good time to talk about the flu. Three years ago we had an unusual flu season, with a nasty variant about that seemed to be threatening a pandemic, and that's the year Huxley was born (in November) so we faced the problem of getting an off season flu shot and not being a member of a Fortune 500 company. We also faced the problem of varying levels of understanding of the flu, and varying odd beliefs about it, among people to whom newborn Huxley might be exposed. This year, my S-I-L is expecting to produce an offspring some time over the next two weeks, so she's dealing with the same concerns. Also, this year is a non-typical season (as, of course, many seasons are). The rate of Influenza infection seems to be rising early. This could mean one of two things (or something in between). It could mean that we are having a flu season that will look normal once it is all over, but shifted early, or it could mean that we are having a very bad flu season, which will have a high peak rate of infection, and what we are seeing now is just the beginning.

I'm not an epidemiologist, so I don't monitor and report on disease. But I am a science blogger and an anthropologist so I do monitor what people are saying about the flu with the idea of addressing potential misconceptions. This post is, essentially, a reaction to what I'm seeing on facebook and in other social networking worlds.

What is the flu shot for?

The flu shot is for Influenza. If you have a flu shot this year, it will signal your immune system to prepare itself for the invasion of three different strains of flu. If you are an average adult person with no notable medical issues, this will likely make you more unlikely to get the flu than you were before the shot. If you are older, or very young (under 2?) or have any immune issues or are just on the wrong end of the curve, you will gain only moderate protection against the flu, but that's better than nothing.

Will I get sick after getting the flu shot?

First, let's be clear: You can't get the flu from the flu shot. The flu they shoot into you is dead. You're not that special that you can bring dead things back to life. There can be side effects but they are typically mild. If you got really sick after getting the flu shot some time in the past, chances are something else has happened.

Here in Minnesota, there is a stomach virus going around and a bad cold going around. Julia and I got our flu shots many weeks ago, Huxley and Amanda got theirs much more recently. All four of us got sick after Huxley and Amanda go their shots. Clearly, we have the local crud, and not the flu.

The "mist" vaccine is not dead, it is merely very beat up. The side effects from the mist are a bit more likely and a bit more severe when they happen. The upside of the mist, other than that you don't get stuck with a needle, is that it is thought to last longer or be more effective.

How long after I get the shot will it start to protect me from the flu?

If you are an average adult, not too old, not too young, etc., your immune system will build the antibodies to the flu strains covered by the shot in about six or seven days. The CDC will tell you "two weeks" before the shot is effective. This is to cover the fact that for some people it can take up to about two weeks. But for many people it is closer to one week.

Can I still get the flu if I get the flu shot?

This year's seasonal influenza shot is typical in that it covers the three flu strains that influenza experts think are the most likely to affect people in the US. It is hard to say what level of effectiveness will pertain in a given year. Various studies suggest that if you are exposed to the flu for which you have been vaccinated there is about a 30% to 50% chance of getting the flu compare to someone who would get it, and if you do get it, you'll have a reduced degree of illness.

Can the flu shot protect me from anything other than what it is designed for?

Yes and no. If you are exposed to a flu that is not one of those in the shot, you still might have a reduced chance of getting that flu, or reduced severity if you do get it. It all depends on the complex interaction between the flu and your immune system, and how your immune system was altered by the vaccine.

I've noticed people saying that the flu shot protects you from a variety of other respiratory diseases that are not the flu. As far as I know, that is highly unlikely. It would be kind of amazing if true. Don't count on it.

Do I really have the flu?

There's a good chance you don't. This is tricky. People who feel really sick and think they have the flu might go to the clinic. Some of them might get tested to see if they have the flu. Of those who are tested, only about a third or a bit more test positive. I don't know enough about the test to evaluate that. Perhaps they have a flu the test does not cover, or perhaps they have some other illness.

A health professional told me something that seems rather unbelievable about the flu. What should I do?

I have all the respect in the world for nurses, having been nursed by them a number of times and all, but ... I've seen both wise and accurate advice and some of the dumbest wrongest things I've heard said by them regarding the flu. Having said that, the really wrong stuff is almost always someone on the internet, so how do we really know they are nurses? They probably aren't. The nurses I know personally are smart about the flu. (Clarification: The fact that the person who claims to be a "nurse" who says the most wrong stuff is on the internet does not mean or imply that other people who claim to be nurses on the internet are automatically wrong. Further clarification: Being a nurse and misleading people about health advice is way bad. Claiming to be a nurse when you are not so that you can push your anti-Vax strategy or do some other unethical thing is bad in a different way. The particular case I'm thinking of is in a recent "ask me anything" web site page where a person claiming to be a nurse went on and on about the dangers of vaccines imploring everyone not to get any vaccines. A different person who also claimed to be a nurse dressed that person down and provided factual accurate information.)

But, if you hear something funny from anyone you can check it out. The CDC has a pretty good bunch of information about the flu. Their main flu page is here, and you can find links to all sorts of information thereon.

What about people having babies during flu season. What do they do?

This is an issue we dealt with three years ago when Huxley was born during a major epidemic of a nasty flu. As I mentioned, my S-I-L is dealing with it now. Here's a few things you should know:

The part of the immune system that protects a person from the flu does not exist in new born humans. They won't have that ability for many months (I see "six" as a commonly used number). This means that if your new born is exposed the flu, and gets it, you've got a serious problem. The best way to avoid this is to avoid contact with anyone who is sick, or for that matter, anyone who has not had a flu shot. You can be sure that everyone in our family was tied down and stuck with a needle three years ago!

Some people harbor the belief that a mother's immunity to the flu is passed on to the baby. This can not be true because that part of the baby's immune system does not exist yet. Some people believe that the mother will pass on to the baby immune products via her milk to protect the baby from things like the flu. This is not really true. The total amount of immune stuff that is passed on to the baby is much smaller than one might hope. If the mother is immune to a particular strain of flu (having had a flu shot, perhaps) that immunity will not protect the infant from that flu, and even if it did, there will be no protection from other forms of the flu.

The best strategy is for all people in the child's household to get a flu shot, avoid lots of interaction with other people, and keep a bottle of hand sanitizer around and make everyone use it.

This, by the way, is where nurses can be especially helpful. If you are having the baby in the hospital or some other place where there are nurses, ask their advice. Pediatrics nurses are well versed in flu related issues vis-a-vis babies. Also, they are IRL nurses, not fake Internet nurses.

So, should I get a flu shot?

Yes. But if you are still not sure, do this. Go to your local clinic. Go to the waiting room. Hang out with the people in the waiting room, the ones who look half dead with illness and are wearing masks, waiting for a doctor to see them and send them home with little more than advice to take something for the fever and headache and drink lots of fluids. They're the people who didn't get flu shots. Spend a little time with them, and maybe you can get the flu too!

Or alternatively, you can hold your breath on your way past the waiting room to the place they give out cheap or free flu shots and just get one.

But, but, I heard about this person who got the flu and died from it and they had the flu shot and this other guy who....

OK, OK, hold on a second. In Minnesota, that happened. A child sadly died form the flu, but had had the flu shot. Here's the thing. Every day in Minnesota there are thousands of people at the clinics who are sick and think they have the flu. Of them, many do. For every one of them, there are many, probably something like 20, that did not got to the clinic. So, we have many thousands of people at any moment in time who have the flu. For some, the shot was not effective, and for some, the flu is deadly. The juncture of those two unfortunate circumstances is unlikely, but given enough chances, unlikely things happen. That is why that child died.

But lots and lots of other people got the shot, were protected, did not get sick, and of them, a small number would have died, but their lives were saved.

Also, there is herd immunity. Last year we almost didn't have a flu season, and I think that may be because so many people got flu shots that year. A couple of years ago we seem to have put off an epidemic, because so many people got immunized against the coming plague, as it were. Everyone who gets the flu can thank a number of individuals who did not get the flu shot for that gift. When you get the shot you give the more difficult to detect gift of not giving the flu to some other person. Not every time, not every year, but over time, that's a give you give again and again. If you get the shot.

Finally, of you don't get the shot you can't see the baby until it's in college!


More like this

I got the shot in November, local blood bank gives them free to donors.

One of my favorite things about the 21st century is that I can get a flu shot in at the supermarket.

One of your "favorite things about the 21st centurey is that you can get the flu shot at the supermarket."? That's one of your favorite?

That is one of my favorite things too. I admit, though, that Todd has a point there ... gruebait and I may be missing something here ....

I lost a healthy adult male friend to the flu a few years ago. It's potentially a very nasty virus, and a little sore spot on the arm is a small price to pay for protection.

Except it doesn't offer much protection at all: You get very mediocre protection against a tiny selection of the viruses going around and that mediocre protection lasts a single season.
At enormous effort. (Numbers vaccinated v. incidents of morbidity avoided)
To vitiate a risk that is absolutely minuscule.
And introducing new risks associated with seasonally rushing the vaccine to market.

Doesn't add up. I do risk management for a living.

By Vince Whirlwind (not verified) on 14 Jan 2013 #permalink

Vince, that is inaccurate. The change in risk is not minuscule. In two alternative universes, where in one you don't get a flu shot and one in which you do, the chance of getting the fu (in the second) if you get it in the first is reduced by about 60% for the average person who has nothing special going on with them. For specific flu strains the reduction is much more, and often especailly bad strains are targeted. In cases where you are on the 40% side of that, chances are you'll have reduced effects and a shorter bout if you do get it.

Please refrain from spreading misinformation about the flu on this blog.

Hmmm - I wouldn't accuse him of spreading misinformation without citing some sources (not that he cited anything either, to be fair). The protection the vaccine confers of course depends how closely it matches the current season's strain of influenza. According to this Cochrane review (which they say may be overly optimistic due to publication bias and missing trial data), the benefits are indeed rather modest.…

Rob, the original post cites the sources. I did not give a figure for the match between a vaccine and a virus strain. I gave a figure for the protection against flu (that is out there for you to get, in its myriad forms) by a vaccine in a given year. There are a dozen studies showing different results across a range of results.

The particular study you cite shows that if there is a good match you get 75% protection, if there is a poor match you get 50% protection. Click through to the resources I cite above for a page with many studies, read them all, report back.

Keep in mind that a phrase like "10% of circulating virus" means that if there are 100 known circulating virus strains, 10 strains makes up 10% of the list of virus strains, not 10% of the exposure events one is likely to encounter.

I get one every year now because my wife is a Type 1 diabetic and any immunological illness is particularly dangerous to diabetics . Fortunately it's free for spouses and people over 65 - otherwise it's $20

By Doug Alder (not verified) on 15 Jan 2013 #permalink

While you're answering flu vaccine questions, I have one, too, which you may be able to answer:
I'm aware that in the US, the CDC usually recommends flu-shots for almost everyone. I'm living in Germany and here (and as far as I know in a couple of other EU countries) the recommendations are different. Only people at high risks (people above 60 years and other risk groups) should get the shot by default.

Now here's my question: Is there any difference between flu in the US or the EU? Are the risks higher in the US? If yes, why? Or is the difference merely one of "different people came to different conclusions while seeing the same evidence, which is inconclusive"? (meaning: We need more/better research?) And after all: Should I get the vaccine next season although I'm not in a risk group?

There are a number of differences between vaccine policy in the US and various European countries, with vaccines generally more recommended in the US than in Europe. In fact, some of our mini-epidemics in the US (like Measles) start with a European bringing us a little gift.

The flu shouldn't be different in Europe vs. the US, an in fact, the German recommendation is interesting. The flu vaccine can be thought of as effective for people who are not at risk at about a 60+% level. But for older folks, for whom it may be more important, it is probably less effective. So, if everyone in Germany followed the recommendations, older people would be much more at risk because there would be more flu circulating around for them to be exposed to.

I think it is, as you say, different people coming to different conclusions. Offhand I'm not familiar with the comparative epidemiological studies (I assume there are some). That would be interesting to look at.

Good question.

On the first link: This is cherrypicking. Effectiveness of the vaccine is not determined by MMR reports, but by a number of sources. (Note also that the best estimate is never going to be data from the first few weeks of a growing epidemic, that's a snapshot of limited usefulness). So the guy is making an argument on the basis of a very limited, cherry picked set of data. This is more an estimate of the prevelence of non-influenza illness causing ILI alongside the flu. Second, if he things hazzard analysis is not appropriate for this sort of study, then his first claim (that he knows what he is doing) is in question.

I regard this as a likely antivaxer site and may delete the link to it. No links to antivaxer sites allowed here, or other rambling about it for that matter. They have their own sites.

I don't think so, Greg. Looks pretty solid to me, but I can't vouch for the bloggers. Criticizing statistics is the national pastime. A reduction in effectiveness from, say 50% to 30% doesn't really change the calculus.


That is still in conflict with the best available information which says 60%.

But, I'm sure there will be some who will take your comment as an excuse to not get stuck, they'll go ahead and get the flu, and grandma will be dead by the end of the month.

Keep a good thought, Greg!


So, should I get a flu shot? I would say yes. If you are afraid of dying from the flu and the thought of a vaccine might ease your fear, then by all means go get one.

thats a ridiculous argument that I should be injected with crap to save u or your kids. Give THEM the flu shot and they won't get it then it won't matter if I got it or not they r protected. It's my right to not be injected with garbage the lying CDC says is safe

Eri, you are wrong. The flu shot is not 100% effective. So you not getting a vaccine is not only a bad decision on your part but that puts at risk people you come into contact with who have not had the shot and, to a lesser extent, people who have had the shot but who are not immunized against the strain you happen to have. So,your refusal to vaccinate yourself and (presumably) to oppose the vaccination of anyone you have influence over or responsibility for (if you have kids, for example) is irresponsible.

What makes this worse is the fact, apparently, that you have decided against vaccines out of ignorance. You should learn more about it so you can make a better decision.

This is great information on 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:

By Paul James (not verified) on 04 Oct 2013 #permalink

OK..I am going to give everyone the answers regarding this 2013-2014 flu shot. First, there are 2 shots First the 3 strain shot and the 4 strain shot. About 200 million 3 strain are released and about 32-40 million 4 strain release. The 4 strain is added protection for middle aged and seniors. I got the 4 strain shot and I WAS healthy at the time. 3 HOURS later I was struck down with flu symptoms...extreme fatigue, body aches, headaches pressure behind my eyes, sore throat runny nose and sinus pressure. I sudddenly had flu symptoms. I am tired of hearing that these vacinations don't give you symptoms..I am on my fourth day of "the flu"..and no I was not sick or exposed to risky sick people prior to this. Here's the deal...i talked to my doctor and she said the same thing happened to her mother and it will pass in 4-5 days.....what do I have? what is the CDC not telling DOCTOR said it was a response to the 4 strain flu shot and it would pass in 4-5 days....I am going think about this next year before I get a flu shot...others are getting as sick as I am yet nothing is being said......I will think twice about trusting the government to tell me the truth about flu shots....such a shame never had a problem before...but I don't trust them now...

Regardless of your experience, Nina, the truth is that as flu and cold (and norovirus) season progresses, people are going to get sick. The flu shot takes days to take effect . If you get the flu shot and then get sick right away you may be one of only a few people who happened, by coincidence, to get sick at that moment, but to you it feels causal. That is a perfectly natural thing to feel.

Maybe the four strain shot has an effect. I have not personally looked into this year's flu strain yet, so I can't honestly comment on that. But in general, what happened to you does not happen because of the flu shot.

i love how even lay Americans' default answer to anything is corporate medication, instead of eating right (like eating real food for a start), being active (like, driving less for example) and exercising common sense.