In 2017, SIRVA was included in the Vaccine Injury Compensation Program (VICP), a federal program that can provide compensation to individuals injured by certain vaccines.6 A diagnosis of SIRVA can be considered in patients who experience pain within 48 hours of vaccination, have no prior history of pain or dysfunction of the affected shoulder prior to vaccine administration, and have symptoms limited to the shoulder in which the vaccine was administered where no other abnormality is present to explain these symptoms (eg, brachial neuritis, other neuropathy). Currently, patients with back pain or musculoskeletal complaints that do not include the shoulder following deltoid vaccination do not meet the reporting criteria for SIRVA in the VICP.6
The exact prevalence or incidence of SIRVA is unknown. In a 2017 systematic review of the literature and the Spanish Pharmacovigilance System database, Martín Arias and colleagues found 45 cases of new onset, unilateral shoulder dysfunction without associated neuropathy or autoimmune conditions following vaccine administration. They noted a female to male predominance (71.1% vs 28.9%) with a mean age of 53.6 years (range 22-89 y). Most of the cases occurred following influenza vaccine (62%); pneumococcal vaccine was the next most common (13%).7 Shoulder injury also has been reported after tetanus-diphtheria toxoids, human papilloma virus, and hepatitis A virus vaccines.4,7 The review noted that all patients had onset of pain within the first week following vaccination with the majority (81%) having pain in the first 24 hours. Two cases found in the Spanish database had pain onset 2 months postvaccination.7 Atanasoff and colleagues found that 93% of patients had pain onset within 24 hours of vaccination with 54% reporting immediate pain.4
The Vaccine Adverse Event Reporting System (VAERS) tracks reports of shoulder dysfunction following certain vaccinations, but the system is unable to establish causality. According to VAERS reporting, between 2010 and 2016, there were 1006 possible reports of shoulder dysfunction following inactivated influenza vaccination (IIV) compared with an estimated 130 million doses of IIV given each influenza season in the US.8
Bodor and Montalvo postulated that vaccine antigen was being over penetrated into the synovial space of the shoulder, as the subdeltoid/subacromial bursa is located a mere 0.8 to 1.6 cm below the skin surface in patients with healthy body mass index.2 Atanasoff and colleagues expounded that antibodies from previous vaccination or natural infection may then form antigen-antibody complexes, creating prolonged local immune and inflammatory responses leading to bursitis or tendonitis.4 Martín Arias and colleagues hypothesized that improper injection technique, including wrong insertion angle, incorrect needle type/size, and failure to account for the patient’s physical characteristics were the most likely causes of SIRVA.7
Proper vaccine administration ensures that vaccinations are delivered in a safe and efficacious manner. Safe vaccination practices include the use of trained personnel who receive comprehensive, competency-based training regarding vaccine administration.1 Aspiration prior to an injection is a practice that has not been evaluated fully. Given that the 2 routinely recommended locations for IM vaccines (deltoid muscle in adults or vastus lateralis muscle in infants) lack large blood vessels, the practice of aspiration prior to an IM vaccine is not currently deemed necessary.1 Additional safe vaccine practices include the selection of appropriate needle length for muscle penetration and that anatomic landmarks determine the location of vaccination.1 Despite this, in a survey of 100 medical professionals, half could not name any structure at risk from improper deltoid vaccination technique.9
Cook and colleagues used anthropomorphic data to evaluate the potential for injury to the subdeltoid/subacromial bursa and/or the axillary nerve.10 Based on these data, they recommended safe IM vaccine administration can be assured by using the midpoint of the deltoid muscle located midway between the acromion and deltoid tuberosity with the arm abducted to 60°.10,11 In 46% of SIRVA cases described by Atanasoff and colleagues, patients reported that the vaccine was administered “too high.”4 The study also recommended that the clinician and the patient be in the seated position to ensure proper needle angle and location of administration.4 For most adults, a 1-inch needle is appropriate for vaccine administration in the deltoid; however, in females weighing < 70 kg and males < 75 kg, a 5/8-inch needle is recommended to avoid injury.7
Our 91-kg patient was appropriately administered his vaccine with a 1-inch needle. As he experienced immediate pain, it is unlikely that his symptoms were due to an immune-mediated process, as this would not be expected to occur immediately. Improper location of vaccine administration is a proposed mechanism of injury for our patient, though this cannot be confirmed by history alone. His prior history of traumatic injury to the opposite shoulder could represent a confounding factor as no prior imaging was available for the vaccine-affected shoulder. A preexisting shoulder abnormality or injury cannot be completely excluded, and it is possible that an underlying prior shoulder injury was aggravated postvaccination.
