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Prevent shoulder injuries during COVID-19 vaccinations

As our nation begins a large-scale coronavirus disease 2019 (COVID-19) immunization campaign barely a year since the deadly virus emerged in the US, it is critically important for healthcare workers who administer the vaccine to understand proper intramuscular (IM) administration technique in order to avoid a preventable and disabling occurrence called shoulder injury related to vaccine administration (SIRVA). This is especially important right now, as healthcare workers who may not normally administer vaccines may be called upon to help administer the new COVID-19 vaccines.


SIRVA is a shoulder injury triggered by the incorrect injection of a vaccine into the shoulder capsule (joint) rather than the deltoid muscle. It is caused by using an incorrect IM injection technique or improper landmarking of the IM injection site (the deltoid muscle) that results in the unintended injection of the vaccine (and/or trauma from the needle) into and around the underlying bursa of the shoulder. This results in an inflammatory process that causes injury to the musculoskeletal structures of the shoulder (e.g., tendons, ligaments, bursae).1-3

Symptoms of SIRVA include persistent shoulder pain, weakness, and limited range of motion that typically develop within hours to a few days after receiving a vaccine; these symptoms do not improve with over-the-counter analgesics. The resulting chronic shoulder pain and inability to carry out daily activities that were possible prior to vaccination often lead patients to seek medical intervention. Patients are often diagnosed with inflammatory shoulder injuries (e.g., bursitis, rotator cuff tears, frozen shoulder syndrome, adhesive capsulitis) that do not appear to be any different than routine shoulder injuries, except that the shoulder symptoms started within days of an IM deltoid vaccination.1

How to Prevent SIRVA

The key to avoiding SIRVA is to recognize the anatomical landmarks for identifying the deltoid muscle and to use proper IM administration technique. Proper landmarking of the deltoid muscle requires determining the upper and lower borders of a safe injection zone. First, the patient’s shoulder should be exposed completely. When a shirt cannot be removed, the sleeve should be rolled up or the arm removed from the sleeve rather than pulling the shirt’s neck over the shoulder. To ensure the injection is given below the shoulder capsule, measure 2 to 3 finger widths from the acromion (bony prominence above the deltoid) to identify the upper border of the injection zone. The lower border can be marked by the armpit to ensure the injection is not inserted below the deltoid muscle. ‘Eyeballing’ the injection site is not acceptable. The thumb and forefinger can be used to make a V to outline the deltoid muscle and keep the injection zone visible before injecting the needle at a 90-degree angle. Injections too close to the shoulder capsule can lead to SIRVA, as noted above. Injections below or too far to the side of the deltoid muscle can hit the radial or axillary nerve, respectively, which can result in neuropathy or paralysis.1

Multiple resources related to proper vaccination techniques are provided by the Centers for Disease Control and Prevention (CDC) and the Immunization Action Coalition (IAC). These resources have been compiled in articles by Deborah Wexler, MD, which can be found by clicking here2 and here.3 Many of these resources, including videos, checklists, and e-learning with continuing education credit, have been recently updated and are applicable to the COVID-19 vaccination campaign. Additionally, the University of Waterloo School of Pharmacy in Ontario, Canada, offers a helpful infographic on proper landmarking to prevent SIRVA, which can be accessed here.1


  1. Bancsi A, Houle SKD, Grindrod KA. Shoulder injury related to vaccine administration and other injection site events. Can Fam Physician. 2019;65(1):40-2.
  2. Wexler D. Technically speaking: Prevent shoulder injuries caused by missing the deltoid muscle when injecting vaccines! Immunization Action Coalition. Updated November 19, 2020.
  3. Wexler D. Technically speaking: Let’s get it right! How to avoid shoulder injury with deltoid intramuscular injections. Immunization Action Coalition. Updated November 8, 2018.