Adult pneumococcal and quadrivalent flu vaccinations are the most likely to be associated with later shoulder pain or inflammation, according to real-world data. 

The study of over 3.7 million intramuscular inoculations recorded by a large US healthcare organisation over a year found 371 were linked to shoulder conditions.

Shoulder pain was the most frequently used symptom code. Only 4.6% of conditions post-vaccination were labelled shoulder bursitis, with more than 70% of them following influenza vaccination.

There was, however, considerable variation in the incidence of shoulder conditions after flu shots, with an incident rate of 0.88 per 10,000 vaccinations for standard dose inactivated trivalent influenza vaccine, rising to a rate of 2.21 per 10,000 for cell culture-based quadrivalent flu vaccine.