The skinny on flu shots – Reprise

I originally published a blog post on Flu Shots in December 2015 which is included below with a few edits.  At Thrive Adult Primary Care, we unfortunately will not be stocking flu shots this season.  However, the vaccine is free with just about any insurance in most major pharmacies, and, if you are paying completely out of pocket, typically costs $30-40 in these same locations.  Also many employers provide flu shots to their employees free of charge.  The following information on out-of-pocket costs comes from an external link published earlier this month:

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Yes, in the medical field we recommend annual flu shots for everyone.  We do this for a phenomenon called herd immunity, meaning that we aim to reduce the exposure of individuals who are susceptible to severe disease by immunizing everyone.  Influenza is not your typical cold virus.  It has been known to cause fatal outcomes in certain populations, generally the very young, the very old, and the chronically ill — that is, people whose immune systems tend to be weaker than average.  Healthy individuals with strong immune systems can contract influenza and have it manifest as nothing more than a really bad cold.  However these people are still contagious and therefore may potentially spread the virus to others who are at risk for a worse outcome.  I am typically pushier about advising someone to get the vaccine if they have regular contact with these susceptible individuals, all the more for someone who is one of them.

I have heard the argument that, “every time I get the flu shot, I get the flu.”  Let’s make it clear that it is impossible for this to happen with the injected flu vaccine (and this year the nasal vaccine is NOT recommended at all).  In this formulation of the immunization, it is as if the virus particle has been broken in half before being introduced to the patient.  A broken virus cannot replicate and therefore cannot generate infection.  However the whole purpose of the vaccine is to activate your immune system to generate antibodies so that if the real flu comes along, your body will be prepared.  The activation of your immune system feels a lot like how it would feel when your immune system is trying to fight off the flu in the case of an actual infection.  So some people will potentially develop low-grade fevers, body aches, weakness and fatigue.  This should last no more than a couple of days, and be assured that it is not an actual infection with influenza.  The nasal flu vaccine (“Flumist”) does in fact contain a live virus, enough to trigger an immune response but rarely enough to cause infection.  However for several years in a row, Flumist showed no protective benefit against contraction of the flu virus, so it is not being recommended for the 2017-2018 season.

I do advise patients who are actively ill to avoid the flu shot.  Again, this is not because the vaccine can cause an infection with the actual flu virus, because it cannot.  However, when a person is sick, their immune system is already busy trying to heal them from their current illness.  Giving a flu shot under these circumstances only adds strain to the immune system when it has a job to do; as a result, it may both prolong the active illness and reduce the likelihood of developing an effective immune response against Influenza.

Rare adverse effects are possible with the flu vaccine.  Probably the scariest of these is known as Guillain-Barre Syndrome which is a type of short-term paralysis that starts in the feet and legs and may ascend to the upper body.  This is exceedingly rare, but of course anyone who has had this type of reaction to the flu vaccine in the past should avoid it in the future.  Also, the majority of available flu shots are prepared using eggs, so folks with an egg allergy should ask whether an egg-free preparation is available where they are planning to receive the flu shot.  In general, anyone who has been able to tolerate the flu shot in the past should have no problem with the shot this year, either.

Finally, on rare occasion a savvy patient will bring up the presence of a mercury compound in the flu vaccine. This is thiomersal, or thimerosal, which is a widely used antiseptic preservative that suppresses the growth and reproduction of common bacteria. It does metabolize the the human body to a form of mercury that can be toxic in significant amounts. However the quantity of thimerosal in a dose of flu vaccine is less than 2.5% of what is considered safe daily intake. Meanwhile a flu shot is needed only once a year. If you want to reduce your body’s exposure to toxic chemicals you would be better off monitoring your daily intake of sugar, salt, or artificial sweeteners. But that is a blog entry for another day. 😉

All of that said, recommendations are merely that. In medicine, we base our advice on the science of statistics. What we recommend IN GENERAL will offer protection against bad outcomes in the population. But each person needs to make a well-informed decision for his- or herself about what advice they will follow or decline. It is my goal to ensure that the decision you make rests on a foundation of solid information.  In all cases, my wish for you as a reader is that you STAY WELL this cold-and-flu season!

2017-10-30T23:44:33+00:00