SIRVA is a rare condition that affects the shoulder after a vaccination. The reason it happens has less to do with the contents of the needle, than how it is placed in your arm. SIRVA stands for "Shoulder Injury Related to Vaccine Administration." You may have noticed that the title of the injury gives a clue to when and how it happens: at vaccine administration.
Vaccine needles are supposed to be placed in the deltoid muscle. However, if the needle goes beyond the muscle into the joint space or shoulder bursa, which sometimes occurs if the needle is placed too high in the shoulder, there will often be an inflammatory response. That inflammatory response can lead to some fairly common shoulder conditions such as bursitis, rotator cuff tears, or adhesive capsulitis (also known as "frozen shoulder").
Often patients who have a SIRVA will be diagnosed with these or similar conditions. The only difference between these conditions and SIRVA is that these conditions will have appeared within a couple of days of a shoulder-administered vaccination. Therefore, SIRVA describes the improper placement of the needle which results in the above shoulder injuries.
If you experience extreme pain and limited arm mobility which starts within days after a vaccination and lasts for longer than just a few days, you may have a SIRVA. If that is the case, you should see your healthcare provider as soon as possible.