Some case studies have reported the development or worsening of pre-existing PMR within 3 months of influenza B vaccination. In the present case series from France, seven cases of new PMR and three cases of exacerbated PMR were described after vaccination against COVID-19 with Pfizer or Moderna vaccines. Interestingly, the symptoms occurred on average ten days after vaccination.
All ten patients who developed PMR symptoms after vaccination underwent thorough examinations: hip ultrasounds, 18F-FDG PETs and CRP levels were obtained. All patients met the 2012 ACR/EULAR criteria for PMR. Other differential diagnoses such as rheumatoid arthritis were ruled out. Therapy with standard therapeutics led to symptomatic improvement.
When PMR occurs after influenza vaccination, the assumption is that it may be related to an additive in the vaccine. COVID-19 vaccines do not contain this additive. However, it is possible that the PMR is triggered by an over-activation of toll-like receptors.
France saw a sharp increase in PMR cases after the start of mass vaccination of the population against COVID-19: from six cases in 2018 and 2019, to three cases in 2020 – when lockdowns played a major role – to 12 cases in 2021. However, it is not impossible that patients would have developed PMR regardless of prior vaccination.
Vaccination against COVID-19 with mRNA vaccines might induce or worsen polymyalgia rheumatica. However, patients respond well to standard treatments and the prognosis in this case series remained unchanged compared to PMR without any relation to vaccination. In the global vaccination campaigns, physicians should be aware of the possibility of PMR occurring after inoculation so that appropriate therapies can be initiated. In addition, patients with corresponding symptoms should be asked for their vaccination history.
Source:
Ottaviani S, Juge P-Antoine, Forien M, Ebstein E, Palazzo E, Dieude P, Polymyalgia rheumatica following COVID-19 vaccination: a case-series of ten ´ patients, Joint Bone Spine