The flu vaccine: Separating Fact from Fiction

Updated: Dec 4, 2020

The flu vaccine: Fact vs. Fiction

It’s flu season again. That means it’s time to get the flu shot.

The flu is a highly contagious respiratory viral illness that infects the nose, throat and lungs. The severity of illness varies and in some cases it can be fatal.

Like many things related to medicine and public health, there are many misconceptions about the flu and flu vaccine that are fed by mis-information campaigns by those who either have a sinister agenda or are ill informed.

Here we will address some of the more common misconceptions about the flu shot and separate fact from fiction.

But first, a little information about the flu and the flu shot.

In the United States, the Advisory Committee on Immunization Practices (ACIP) recommends getting a flu shot every year for everyone six months and older.

The flu vaccination is especially important during the 2020-21 influenza season because it will coincide with raging pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Symptoms of influenza and SARS-CoV-2 cannot be distinguished without specific testing for both viruses. However, the flu vaccine could reduce risk of simultaneous coinfection with both viruses.

Those at extremes of age along with those who have underlying medical problems are at increased risk of developing complications from the flu, including death. In this group as well as in all individuals the flu shot not only reduces the risk of influenza infection but also reduces the severity of illness in those who are infected.

The influenza virus has a high rate of mutation, compromising the ability of our immune system to protect against new variants. Because of this, new vaccines are produced each year to match circulating viruses.

Making the vaccine for the coming flu season takes about six months to produce.

The decision of what viral antigens to include in the vaccines for the following year is made in advance of the influenza season and is based upon global surveillance of influenza viruses circulating at the end of the prior influenza season.

This means that it is possible for mismatches between the vaccine strain and the circulating strain that result in reduced efficacy of the vaccine. This is rare.

The two main strains responsible for the flu are types A and B. The current influenza vaccines are trivalent or quadrivalent. The trivalent vaccine contains two influenza A virus antigens and one influenza B virus antigen, whereas the quadrivalent vaccine contains two influenza A antigens and two influenza B antigens.

The flu shot is recommended every year even if the previous year's vaccine contained one or more of the antigens because the bodies immunity declines during the year following vaccination.

The theme of this post: The best way to protect yourself from the flu is to get vaccinated. The flu shot reduces mortality by about 40 to 60%.

The flu vaccine comes in two doses. One is the standard does and the other is a "high dose" version of the vaccine. The high does vaccine has four times the antigen when compared to the regular vaccine.

Both of these vaccines are quadrivalent vaccines. The higher dose vaccine is intended to help older people develop a more robust immune response. This in theory should provide better protection against flu. Both these flu vaccines produced by the same manufacturer.

Now let’s tackle some of the common misconceptions and separate fact from fiction.

The flu is not that big of a deal.

While mild cases of the flu may feel like a bad cold, it can actually be a serious threat to your health. In the United States more than 30,000 people die from the flu and thousands more are hospitalized because of the flu virus.


I am young and healthy so I don’t need the vaccine.

Everyone benefits from getting the flu shot. The current CDC recommendation is yearly flu vaccination for everyone without a contraindication that is older than 6 months old.


The flu vaccine will give you the flu.

This is the most common misconception about the flu vaccine that is out there. The flu shot is an inactivated virus.

That means there is no biological way it can “give you the flu.”

Couple of things can happen after a flu vaccine that leads to the incorrect assumption that the flu shot caused the flu. If you get sick right after the flu shot, you were likely exposed days before and were going to get sick anyway, the flu shot timing is just a coincidence. You may have a low grade fever after getting the flu shot, this may be your immune system in action.


I can just take vitamin D instead of getting the flu vaccine.

There have been several studies that show taking vitamin D may reduce the risk of getting the flu. This has not been universally excepted and is definitely not a substitute for getting a flu shot.


I hate needles, the nasal vaccine is a good alternative.

Several studies have shown that the nasal flu vaccine is not as effective as the flu shot.


Vaccines cause autism.

Full disclosure, I have an Autistic child.

One of the funniest (and dumbest) things I have read on this topic is the claim that a perfectly normal child went to the pediatrician, got the appropriate vaccines and went home. By the time the child was home, according to the parents - the child was Autistic.

Autism is a developmental disorder of variable severity that is characterized by difficulty in social interaction and communication.

It does not happen on the drive home from the pediatrician.

Further, several studies have put this question to rest. Vaccines DO NOT cause Autism. There is no debate here, the question has been studied, re-studied and studied again. There is no link.


The flu shot doesn’t work.

The flu vaccine reduces the risk of contracting the flu anywhere from 40-60%. It reduces the severity of the flu even if the vaccine is not perfectly matched to the flu strain for that year. Of note, the vast majority of kids who died from the flu last year were not vaccinated.


Pregnant women should not get the vaccine.

There are ill informed and frankly incorrect claims that the flu vaccine can cause a miscarriage. This is simply false. What is true is the flu can lead to miscarriage. Hence, it is especially important for pregnant women to get their flu shot.


The best way to avoid getting the flu is the vaccine.

Getting a flu shot is the single best thing that you can do each flu season to protect yourself from getting the flu.


There is a lot of misinformation about the flu and the flu vaccine. Getting a flu shot is a personal choice, hence it is important to make decisions based on correct information.

Please remember that medical information provided by us must be considered an educational service only. This blog should not be relied upon as medical judgement and does not replace your physician’s independent judgement. This is NOT medical advice. Please seek the advice of your physician.

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