Accidental vaccine injection into adjunct shoulder structures can cause tissue damage, termed Shoulder injury related to vaccine administration (SIRVA). The immunopathological mechanisms and consequences of SIRVA are unknown.

The study assesses the clinical and immunological consequences of an influenza vaccine if accidentally administered in periarticular space.

Inclusion Criteria:

• participation at a local vaccination campaign
• Shoulder pain >3 days after vaccination

Exclusion Criteria:

• no vaccine received
• preexisting shoulder pathology

Subjects receiving the Influenza vaccine at a local vaccination campaign in Basel, Switzerland

Data on flowcytometry based immunophenotyping