SIRVA (Shoulder Injury After a Vaccine Administration)

What Is SIRVA?

Shoulder Injury Related to Vaccine Administration (SIRVA) is a rare complication that can occur after an intramuscular vaccine injection into the shoulder. Instead of entering the deltoid muscle, the needle may be placed too high or too deep, allowing vaccine material to enter structures such as the subacromial bursa, rotator cuff tendon, or joint capsule. This can trigger inflammation and persistent shoulder pain.

Unlike typical post-vaccination soreness—which usually resolves within a few days—SIRVA symptoms can last weeks or months and may interfere with normal shoulder function. SIRVA is considered uncommon, but well recognized in medical literature. It has been reported after many vaccines, including influenza, COVID-19, tetanus, and others.

A major review from the National Academies of Sciences concluded that certain shoulder injuries—such as subacromial bursitis and rotator cuff tendon injury—can be causally related to improper vaccine injection technique.

Symptoms of SIRVA

Symptoms typically begin within 24–48 hours of vaccination and may include:

• Persistent shoulder pain after vaccination

• Pain with overhead movement

• Limited range of motion

• Shoulder stiffness

• Weakness or difficulty lifting the arm

• Night pain when lying on the shoulder

Patients often report that the pain started immediately after the injection or within the first day, rather than gradually developing over weeks as seen with many degenerative shoulder conditions.

If symptoms last longer than 5–7 days, evaluation by a musculoskeletal specialist may be appropriate.

What Causes SIRVA?

SIRVA occurs when the vaccine is injected into structures around the shoulder rather than into the deltoid muscle.

Possible mechanisms include:

• Injection into the Subacromial Bursa: If the needle enters the subacromial/subdeltoid bursa, it can cause acute bursitis and inflammation.
• Injection into Rotator Cuff Tendons: The rotator cuff tendons lie just beneath the deltoid muscle. Direct injection into these structures can cause tendinopathy or tendon injury.
• Injection Too High on the Shoulder: Vaccines placed too high near the acromion increase the risk of entering the bursa or joint space.
• Immune-Mediated Inflammation: Vaccines are designed to stimulate an immune response. When vaccine components enter synovial structures, they may trigger significant inflammatory reactions in the shoulder.

Evidence suggests that certain injuries—including subacromial bursitis, tendon injury, bone injury, and nerve injury—can occur when injections are misplaced within shoulder structures.

Conditions Associated With SIRVA

SIRVA is not a single diagnosis. Instead, it refers to several potential shoulder injuries that may occur after vaccination. These may include:

• Subacromial / Subdeltoid Bursitis: Inflammation of the bursa above the rotator cuff is one of the most common findings.
• Rotator Cuff Tendinopathy: Inflammation or injury to the rotator cuff tendons, particularly the supraspinatus.
• Adhesive Capsulitis (Frozen Shoulder): Some patients develop progressive stiffness after initial inflammation.
• Biceps Tendonitis: The long head of the biceps tendon can become irritated after injection.
• Nerve Irritation: Rarely, the axillary or radial nerve may be affected.

How Is SIRVA Diagnosed?

Diagnosis is based on a combination of clinical history, physical examination, and imaging.

Important diagnostic clues include:

• Shoulder pain beginning within 48 hours of vaccination

• No prior history of significant shoulder pain

• Persistent symptoms beyond normal post-vaccination soreness

Ultrasound: Musculoskeletal ultrasound is often the first imaging study used. SIRVA has characteristic findings on diagnostic ultrasound that may not be seen on MRI (Learn more here). Ultrasound can identify:

• Subacromial bursitis

• Rotator cuff inflammation or tearing

• Biceps tendon abnormalities

• Fluid collections

MRI: MRI may be recommended in more complex cases to evaluate deeper shoulder structures.

Can SIRVA Be Prevented?

Yes. Proper injection technique significantly reduces the risk.

Recommended prevention strategies include:

• Injecting into the middle of the deltoid muscle

• Avoiding injections too high near the acromion

• Using appropriate needle length

• Proper patient positioning during vaccination

Healthcare providers are trained in these techniques, and SIRVA remains a rare complication relative to the millions of vaccines administered each year.

How is SIRVA Treated?

Treatment focuses on reducing inflammation and restoring shoulder function. Most patients improve with non-surgical care.

Conservative Treatment

Initial treatment may include:

• Activity modification

• Physical therapy

• Anti-inflammatory medications

• Ice and rest

Ultrasound-Guided Injections

For persistent symptoms, targeted injections may help reduce inflammation:

• Corticosteroid injections for bursitis

• Platelet-rich plasma (PRP) for tendon injury

Ultrasound guidance allows physicians to accurately treat the specific injured structure.

Minimally Invasive Procedures: In cases of chronic tendon injury, procedures such as ultrasound-guided tenotomy or percutaneous debridement may be considered to remove damaged tissue and stimulate healing. Learn more here.