Prevalence of Disease Flares Following COVID-19 mRNA Vaccination Among Patients With Arthritis

Nearly one in five patients with RA, PsA, and SpA reported experiencing disease flares following COVID-19 mRNA vaccination, though most were considered nonsevere.

About one-fifth of patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and spondyloarthritis (SpA) experienced disease flares following COVID-19 messenger RNA (mRNA) vaccination, though most flares were considered nonsevere, according to study findings published in Advances in Rheumatology.

Investigators assessed the prevalence of and characteristics associated with disease flares following COVID-19 mRNA vaccination among patients with RA, PsA, and SpA.

The investigators conducted a sub-study of a multi-center, retrospective cohort study across 8 hospitals in Singapore, including patients aged at least 12 years diagnosed with RA, PsA, or SpA who received at least one COVID-19 mRNA vaccine dose (Pfizer-BioNTech or Moderna).

The primary study endpoint was physician-defined flare within 3 months of the first vaccine dose.

A total of 2377 patients (71.6% Chinese, 12.5% Indian, 10.0% Malay) were included in the analysis. Of these, 46% were in disease remission prior to vaccination, 87.6% received the Pfizer vaccine, and nearly all patients (93.2%) had received 2 vaccine doses.

Patients with active disease prior to vaccination should be more closely monitored for disease flares post-vaccination, especially for patients with RA.

Patients receiving disease modifying anti-rheumatic drugs (DMARDs) were mostly treated with methotrexate (58.9% RA; 54.9% PsA), and patients with SpA mostly received sulfasalazine (24.6%). Patients receiving biological DMARDs were mostly treated with tumor necrosis factor inhibitors.

Among patients with RA, 21.3% experienced disease flares, of which 10.2% were severe. Similarly, 24.1% and 21.8% of patients with PsA and SpA experienced flares, of which 11.0% and 14.9% were considered severe, respectively. Overall, 15.2% of all flares required treatment escalation and less than 1% required hospitalization.

Patients with RA who reported higher disease activity prior to COVID-19 vaccination were associated with experiencing flares (hazard ratio [HR], 1.68; 95% CI, 1.22-2.31). Similarly, patients with RA with low or moderate/high disease activity were more likely to experiences flares vs patients in remission (HR, 2.28; 95% CI, 1.50-3.48).

Risk for flare was not associated with disease activity among patients with PsA or SpA.

Patients with PsA receiving the Moderna vaccine vs the Pfizer vaccine were more likely to experience flares (HR, 2.21; 95% CI, 1.20-4.08); this association was not found among patients with RA or SpA.

Patients who received 2 vaccine doses were less likely to experience flares (HR, 0.08; 95% CI, 0.06-0.10), with no significant differences noted between groups.

This study was limited by its retrospective design, lack of control group, and missing data on disease flares prior to the COVID-19 pandemic. Additionally, a causal relationship between disease flare and vaccination cannot be concluded. Finally, the definitions of disease flare within the literature were heterogenous and definitive comparisons could not be made.

The study authors concluded, “Patients with active disease prior to vaccination should be more closely monitored for disease flares post-vaccination, especially for patients with RA.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Fong W, Woon TH, Chew LC, et al. Prevalence and factors associated with flares following COVID-19 mRNA vaccination in patients with rheumatoid arthritis, psoriatic arthritis, and spondyloarthritis: a national cohort study. Adv Rheumatol. Published online August 1, 2023. doi:10.1186/s42358-023-00316-0