Does a flu shot give you a small case of the flu??

Ask most doctors or nurses if a flu shot contains a live flu virus that will make you sick and you will get a different answer… So my question is…does the shot give you a small case of flu to prevent the big case of flu or is it (like my doctor explained to me this year) a dead virus and can’t possibly make you sick or… does it depend on the strain of virus we happen to be battling that year? What’s the deal?

I’m the best there is fats…even if you beat me I’m still the best.
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RWAG (Rational? Wild-Ass Guess): It should be a “dead” virus, that could not cause illness, but would stimulate the immune system. If it were designed to give you a small case of the flu, I don’t know of any way they could guarantee that it would remain a small case rather than becoming full-blown flu.

As far as I understand, although i’ve no specific knowledge with regard to the 'flu virus, vaccines tend to incorporate a small part of the real virus, particularly part of it’s outer structure to enable the body’s immune system to recognise the true virus when necessary, and as such, cannot cause the associated disease. BTW, I consider it wrong to ever describe a virus as ‘living’.

Most virus vaccines produced are created by manipulating yeast organisms to produce proteins from the virus to be prevented. The immune system then is triggered by the same receptors that the real virus will present to them, and an advanced response to the pathogen will allow the body to eliminate infectious viruses before they become destructive. These viral proteins cannot cause the disease they are taken from, since they lack the replicative, and invasive viral mechanism.

One other point, the human response to the vaccine is the same as it is to the virus. That is a necessary consequence to establishing the proper immunological response in the protected individual. In some patients, (such as me) the reaction to most colds is mild, and the reaction to the flu-shot is strong. For me, it is a matter of having a runny nose, and cough, or having a runny nose, and cough, and a sore arm. I generally forget about the shot. Up until I die of sudden onset Influenza in a few short hours, I will be making the right choice.


The Flu shot is dead. NO it doesn’t give you the flu. But people may have an allergic reaction with similar symptoms to the flu. This isn’t the flu.

Does it guarantee you won’t get the flu? No. There are lots of strains of flu. Most people who get the flu will have a milder case if they get the shot.

This is best indicated by the example of the polio vaccine. The oral kind can cause polio. It is a live virus. Virus may not be alive but they can have that quality. The polio shot is a dead virus and doesn’t cause the disease.

In any case the flu isn’t a cold and the flu shot will not protect against a cold.

Sue (majormd) and I answered this in another thread which I can’t find because of the stupid search engine’s crankiness.

Anyway, the short answer is: With flu shots, there are no live viruses involved. You can’t catch a virus from dead viruses.

Mild flu-like symptoms occur anyway because your body thinks it has been affected and produces the antibodies for the virus. In thinking it is infected, your body goes into fight-mode, which can include raised temperature, achiness, and other flu-like symptoms.

That’s right, most of the pain and misery of a flu comes from your own body waging viral war and not from the direct effects of the virus. And with a flu shot, your body starts to wage a war against the dead. But that’s the point, when the real live virus shows up at some point, your body knows just how to handle that bugger.

Sue had a wonderfully technical answer to this in that other thread.


The Flu shot is a cocktail.

Yep, its usually the four most prevalent strains.

Thus, you can still get the flu even if you get a flu shot cause there are tons more viruses than just four.

Ditto to all who said that you cannot get the flu from a flu shot.

Each year’s flu shot stimulates your immune system to make antibodies against the strain(s) of type A & type B influenza expected during the coming flu season (generally Nov-March; this year’s seem to be a little early.)

The vaccines cause the various cells in the immune system to become active. In order for then lymphocytes to begin making the desired antibodies, a number of cell-to-cell interactions must occur. These are usually accomplished by chemicals called cytokines which are secreted by immune cells to cause some effect on other immune cells.

Unfortunately, many of the symptoms caused by an infection are the result of some of these cytokines, rather than a direct effect of the virus/bacteria itself. For example, a person can have Hepatitis C & feel fine. If (s)he takes interferon for it to try to fight it, (s)he’ll feel tired, achy, irritable, & feverish.

Individuals fortunate enough not to have experienced a full-blown case of influenza may develop these symptoms after a vaccine, due to the immune system stimulation, & mistakenly believe they have the flu.

Sue from El Paso

Experience is what you get when you didn’t get what you wanted.

Wow! good answers everyone I may be out of my league here…I had a flu shot this year and didn’t have any symptoms whatsoever, so I consider myself lucky…Thanks all!

I think I saw on the tv some new medicines that you can take when you have the flu that make it much shorter. Rx stuff. Seems legit, whats the story on those?

From the CDC Flu Vaccine Information page.

As for anti-flu medications, I know that a drug known as Relenza is avaiable Down Under. It’s a neuraminidase inhibitor. Not like you care :slight_smile:

Back off, man. I’m a scientist.

In reviewing my answer, I think it suggests that many/most people feel cruddy after a flu shot. In fact, most people have no symptoms whatsoever.

But some people do get symptoms & vociferously spread misinformation about getting the flu from the shot.

As for treatment, Amantadine has been around for years, but only treats type A, and must be started within 24 hours to do any good.

There is a new one out this year, effective for both type A & type B. I don’t know the name of it off the top of my head, but Relenza sounds familiar. This is what the ads are referring to when they urge you to call your doc right away if you think you have the flu.

Sue from El Paso

Experience is what you get when you didn’t get what you wanted.

I got a flu shot from my company this year and had no reaction at all.

I was just wondering how do they know what strains of flu to expect this year? Is there some animal host that serves a a reservoir?

Virtually yours,


I asked the same question (how do they know which strains to use) and was told that they track flu outbreaks in other count and use those strains. So we get shots containing the flu that was causing trouble in Singapore or somewhere earlier in the year. Just tough luck for the people in Singapore, I guess.

Other countries, that is.