Getting the flu shot is never a bad idea. Versions of the vaccine have been around for more than 70 years, according to the Centers for Disease Control and Prevention.
Basically, the flu shot is safe, reliable, and its benefits outweigh any small risks that may be associated with the vaccine. So, as long as you’re over six months of age, get it.
However, it’s important to be aware of the risks that can accompany the flu vaccine. Typically, they include pain, swelling, and redness around the site of the injection—much like any shot—which may appear 24 to 48 hours after the actual shot.
If a flu shot isn’t properly administered, it can result in a type of shoulder injury commonly referred to as Shoulder Injury Related to Vaccine Administration, or SIRVA.
What is SIRVA
SIRVA is a condition in which pain and loss of function in the shoulder occurs following a vaccination—usually within 48 hours of administration of an injection in people who had no shoulder issues prior to injection. It can result in shoulder pain, weakness, stiffness, or nerve inflammation. In rare cases, it can result in nerve injury.
While any sort of vaccination can lead to SIRVA, researchers found the majority were the result of the influenza vaccine. According to the report, nearly all who have reported such an injury developed it within 24 hours.
So, why does SIRVA happen?
When a needle is injected too deep the deltoid muscle can be penetrated and structures within the shoulder can be damaged such as the rotator cuff, joint capsule, as well as the axillary or radial nerves in the upper arm could be injured. A 2018 study specified that it “occurs when an injection is administered too high in the arm, and the vaccine is delivered to the shoulder capsule instead of the deltoid muscle.”
What are the symptoms of SIRVA—and how is it treated?
While dull muscle ache pain after a vaccine injection is common, it usually disappears on its own with days. With SIRVA, on the other hand, an individual will usually start feeling pain within 48 hours of the vaccination, and doesn’t improve.
In patients who experience SIRVA, months may pass by, and patients will still complain of increasing pain, weakness, and impaired mobility in the injected arm. Simple actions like lifting your arm to brush your teeth can cause pain.
In order to diagnose SIRVA, an ultrasound scan is needed, which can also determine the level and type of damage. Inflammation reducing oral medications and corticosteroid injections to the shoulder are common treatments for SIRVA, and additionally, physiotherapy may be recommended.
Can SIRVA be prevented?
Health care providers who administer vaccinations need to use proper vaccination landmarking techniques. It’s important to let the people administrating vaccinations see the entire shoulder, so that they can reference the necessary landmarks for proper injection. Wear a sleeveless shirt or shirt that can be removed in order to reveal the entire shoulder. Rolling up the sleeve may prevent the person administering the vaccine from seeing all of the landmarks necessary to administer appropriately.
But again, just for good measure, keep in mind that SIRVA is rare, and is certainly not a reason to avoid getting the flu shot. My advice is to still be vaccinated as you normally would but to talk to your primary care doctor about any concerns you may have.