Pasadena, CA—Shoulder injury related to vaccine administration (SIRVA) might be extremely rare, but it happens. Is there anything pharmacists and other vaccinators can do to help avoid those problems?

A study team from Kaiser Permanente Southern California sought to estimate the risk for shoulder conditions after vaccination, as well as determine possible risk factors.

The retrospective cohort study involved Kaiser Permanente Southern California members aged 3 years or older who had an IM vaccination administered in the deltoid muscle between April 1, 2016, and December 31, 2017. Results were published in Annals of Internal Medicine.

Among 3.7 million administered vaccinations, chart review identified 371 cases of shoulder conditions for an estimated incidence of 0.99 (95% CI, 0.89-1.09) per 10,000 vaccinations. Researchers determined that the incidence was 1.22 (CI, 1.10-1.35) for the adult (aged >18 years) and 0.05 (CI, 0.02-0.14) for the pediatric (aged 3-17 years) vaccinated populations. For adults, a higher risk for shoulder conditions was found in those of advanced age, female sex, with an increased number of outpatient visits in the 6 months before vaccination, lower Charlson Comorbidity Index, and receipt of pneumococcal conjugate vaccine. Quadrivalent influenza vaccines were also associated with an increased risk for shoulder conditions, and simultaneous administration of more than one vaccine was associated with a higher risk for shoulder conditions among older recipients, researchers advised.

"These population-based data suggest a small absolute risk for shoulder conditions after vaccination," the authors concluded. "Given the high burden of shoulder conditions, clinicians should pay attention to any factors that may further increase risks."

Another recent study also discusses the issue. The report in Clinical Orthopedics & Related Research noted that an immune-mediated inflammatory response to a vaccine antigen injected into or near the subacromial bursae or synovium can lead to shoulder pain and dysfunction.

Johns Hopkins School of Medicine–led researchers conducted a systematic review of research on the condition, asking about clinical characteristics, diagnoses, and management approaches and outcomes reported in association with SIRVA. They pointed out that although shoulder conditions have been reported as an adverse event after IM vaccination in the deltoid muscle, epidemiologic data remain limited.

On October 4, 2021, they searched the PubMed and Medline databases for studies related to SIRVA. Inclusion criteria were English-language comparative studies, case series, and case reports that involved shoulder pain occurring after vaccination. Studies of exclusively neurologic conditions after vaccination were excluded. Meeting the eligibility criteria, including the involvement of shoulder pain occurring after vaccination, were 42 studies, including three retrospective comparative studies (72 patients and 105 controls), five database case series (2,273 patients), and 34 case reports (49 patients).

The median age for patients in the case reports was 51 years (range 15-90 years), and 73% (36 of 49) were women. BMI was reported for 24% of patients (12 of 49) in case reports, with a median of 23.5 kg/m2 (range 21-37.2 kg/m2).

The authors listed the most common symptoms as shoulder pain and reduced range of motion. They reported that the most common diagnoses were shoulder bursitis, adhesive capsulitis, and rotator cuff tears, while the most frequent management modalities included physical or occupational therapy, nonsteroidal anti-inflammatory drugs, and steroid injections. Surgery was generally limited to patients whose symptoms persisted despite nonsurgical management. Full resolution of symptoms was reported in 2.9% to 56% of patients.

"The association between inflammatory conditions of the shoulder (such as bursitis) and vaccination appears to be exceedingly rare, occurring after approximately 1:130,000 vaccination events according to the best-available comparative study," researchers advised. "Currently, there is no confirmatory experimental evidence supporting the theory of an immune-mediated inflammatory response to vaccine antigens. Although the clinical evidence is limited, similar to any bursitis, typical treatments appear effective, and surgery should rarely be performed. Additional research is needed to determine the best injection technique or evaluate alternate injection sites such as the anterolateral thigh that do not involve positioning a needle close to the shoulder."

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