Publication date: Aug 21, 2026
Patients receiving disease-modifying antirheumatic drugs (DMARDs) and biologic therapies were underrepresented in initial COVID-19 vaccine trials, limiting understanding of vaccine effectiveness in immunosuppressed populations. While immunogenicity studies demonstrate reduced antibody, real-world outcome-based evidence remains limited. We evaluated the association between COVID-19 vaccination and clinical outcomes among hospitalized patients receiving systemic DMARDs and biologic therapies. We conducted a retrospective cohort study across seven hospitals within the UPMC health system in Central Pennsylvania. Adults (≥ 18 years) hospitalized with COVID-19 between March 2020 and April 2025 and receiving immunomodulatory therapy. Vaccination status was determined using electronic health records and registry-linked coding data, with vaccine type and SARS-CoV-2 variants also assessed. The primary outcome was hospital length of stay (LOS). The secondary outcome was in-hospital mortality. Multivariable logistic regression and gamma regression models adjusted for key demographic and clinical covariates. Among 254 patients, 144 were vaccinated and 110 were unvaccinated. One hundred twenty-eight vaccinated patients received at least one booster. Vaccinated had shorter median LOS (6 vs. 10 days; p
| Concepts | Keywords |
|---|---|
| 10days | Biologic therapy |
| 18years | COVID-19 |
| Pennsylvania | DMARDs |
| Underrepresented | Hospitalization |
| Vaccinated | SARS-CoV-2 |
| Vaccination |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | COVID-19 |