Published February 2, 2021 (revised October 19, 2023)
The COVID-19 vaccines, the Respiratory Syncytial Virus (RSV) vaccine and most childhood vaccines are given by injection into the muscle (intramuscularly, IM). For adults and young children over the age of 1 year, the deltoid (upper arm) muscle is often the preferred site for giving IM vaccines. It is important for healthcare workers who administer vaccines to know how to give an IM vaccine properly to avoid a preventable and disabling shoulder injury called “shoulder injury related to vaccine administration (SIRVA).”
A woman reported that she went to her local community pharmacy to receive the influenza (flu) vaccine along with the Shingrix (zoster) vaccine to prevent shingles. The pharmacist injected one vaccine into each upper arm. When he injected the Shingrix vaccine into her right upper arm, the woman experienced severe pain—more than she had ever felt upon receiving previous vaccinations. Later that evening, the pain in her right shoulder became intolerable. She was finally able to fall asleep after she applied ice to her shoulder. Two months later, the woman reported that she still had problems with her shoulder. For example, she was not able to reach for things or move her shoulder in certain ways without experiencing pain and discomfort. So, what could this be? SIRVA could be one explanation.
SIRVA is a shoulder injury triggered by the incorrect injection of a vaccine into the shoulder joint rather than the deltoid muscle. It happens when healthcare workers do not properly locate the deltoid muscle in the upper arm and instead inject the vaccine into and around the shoulder joint. This (and/or trauma from the needle) can cause inflammation and injury to the shoulder tendons, ligaments, or bursa (small fluid-filled sacs that reduce friction when moving your shoulder).1-3
Symptoms of SIRVA include persistent shoulder pain, weakness, and inability to move the arm without pain. These symptoms develop within hours to a few days after receiving a vaccine and do not improve with over-the-counter pain medicines. The resulting chronic shoulder pain and inability to carry out daily activities that were possible prior to vaccination often lead consumers to seek medical attention. 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 hours or days of an IM deltoid vaccination.1
The key to avoiding SIRVA is making sure that healthcare workers can identify the deltoid muscle and are using the proper technique to give the IM vaccine. This means that the healthcare worker must determine the upper and lower borders of a safe IM injection zone (Figure 1). To help them, you need to completely expose your shoulder when receiving an IM vaccine. When you cannot remove your shirt, you should roll up the sleeve completely or remove your arm from the sleeve. Pulling your shirt’s neck opening down over your shoulder may not expose enough of the shoulder and arm to properly identify the safe IM injection zone.
To ensure the injection is given below the shoulder joint, make sure the healthcare worker measures 2 to 3 finger widths from the bony bump (acromion) at the top of your arm (above the deltoid) to identify the upper border of the injection zone (Figure 1). The lower border is marked by the armpit to ensure the injection is not inserted below the deltoid muscle. ‘Eyeballing’ the injection site is not acceptable. Do not be afraid to speak up if you do not see the healthcare worker measuring 2 to 3 finger widths below your bony bump at the top of your arm to find the safe injection site.
Your healthcare worker then might use their thumb and forefinger to make a V to outline the deltoid muscle and keep the injection zone visible before injecting the vaccine. The needle of the syringe should be injected at a 90-degree angle, straight into the muscle. Injections too close to the shoulder joint can lead to SIRVA, as noted above. Injections below or too far to the side of the deltoid muscle can hit a nerve, which can result in nerve damage, even paralysis.1
References
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. www.ismp.org/ext/611
2. Wexler D. Technically speaking: prevent shoulder injuries caused by missing the deltoid muscle when injecting vaccines! Immunization Action Coalition. Updated November 19, 2020. www.ismp.org/ext/613
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. www.ismp.org/ext/614
