Study fiinds, Disease Flare and Reactogenicity not observed
A Study was conducted to evaluate disease flare and post-vaccination reactions (reactogenicity) in patients with rheumatic and musculoskeletal diseases (RMD) following two-dose SARS-CoV-2 mRNA vaccination.

1377 RMD patients who received two doses of SARS-CoV-2-mRNA vaccination submitted questionnaires documenting local and systemic reactions experienced within 7 days of each vaccine dose (D1, D2), as well as 1 month after D2 detailing flare of RMD. Modified Poisson regression was used to examine the relationships between demographic/clinical factors and flares that required therapy.

--11% reported flare requiring treatment; there were no reports of severe flares. Flare was associated with prior SARS-CoV-2 infection (IRR 2.09), flare in the six months preceding vaccination (IRR 2.36) and use of combination immunomodulatory therapy (IRR 1.95).

--The most frequently reported local and systemic reactions included injection site pain (D1 87%, D2 86%) and fatigue (D1 60%, D2 80%); reactogenicity increased after D2, particularly for systemic reactions.

--No allergic reactions or SARS-CoV-2 diagnoses were reported.

It was unusual to see a flare of underlying RMD after SARS-CoV-2 vaccination. There have been no reports of a serious flare-up. Local and systemic reactions did not often impede with everyday activities. These preliminary safety findings can assist alleviate vaccine hesitation in RMD patients.