Novel mechanisms of COVID-19 vaccines raised concern about their potential immunogenicity in patients with rheumatoid arthritis (RA) undergoing immunomodulatory treatments. We designed a retrospective single-center study to investigate their effectiveness and safety in this population, analyzing data from the first vaccination program (December 2020–October 2021). Inclusion criteria were availability of post-vaccination serology and a minimum subsequent follow-up of 6 months. Binding antibody units (BAU/mL) ≥ 7.1 defined an adequate serological response. Post-vaccine COVID-19 incidence and its timing since vaccination, adverse events (AEs), and RA flares were recorded. Adjusted logistic and linear multivariate regression analyses were carried out to identify factors associated with vaccine response. We included 118 patients (87.2% women, age 65.4 ± 11.6 years, evolution 12.0 ± 9.6 years), of whom 95.8% had a complete vaccination schedule. Adequate humoral immunogenicity was achieved in 88.1% of patients and was associated with previous COVID-19 and mRNA vaccines, whereas smoking, aCCP, age, and DMARDs exerted a negative impact. Post-vaccine COVID-19 occurred in 18.6% of patients, a median of 6.5 months after vaccination. Vaccine AE (19.5%) and RA flares (1.7%) were mostly mild and inversely associated with age. Our results suggest that COVID-19 vaccines induce adequate humoral immunogenicity, with an acceptable safety profile in RA patients.

Background: To describe the effectiveness and safety of COVID-19 vaccine in a series of patients with rheumatoid arthritis (RA). Methods: Retrospective single-center study of RA patients, fulfilling the ACR 1987 or ACR/EULAR 2010 classification criteria, that received first COVID-19 vaccine between December 2020 and October 2021, had post-vaccination serology and subsequent follow-up of at least 6 months in a university hospital. Vaccine effectiveness was evaluated by the serological response and the incidence of post-vaccine COVID-19, and safety by the incidence of adverse events (AE) and RA flares. Adjusted logistic and linear multivariate regression analyses were carried out with Stata® to identify factors associated with vaccine response. Results: We included 118 patients with RA (87.2% women, age 65.4±11.6 years, evolution 12.0±9.6 years). 95.8% received complete vaccination schedule. Most patients (88.1%) developed adequate humoral immunogenicity, and the degree of serological response was significantly related to younger age and previous COVID-19 infection. After vaccination, 18.6% presented mild SARS-CoV-2 infection. Vaccine AE (19.5%) were mostly mild and inversely associated with age (OR 0.95). RA flares were anecdotal (1.7%) and inversely related to age (OR 0.95). Conclusion: Our results suggest that COVID-19 vaccine induces adequate humoral immunogenicity, with an acceptable safety profile in RA patients.

Background SARS-CoV-2 viral load and kinetics assessed in serial blood samples from hospitalised COVID-19 patients by RT-PCR are poorly understood. Methods We conducted an observational, prospective case series study in hospitalised COVID-19 patients. Clinical outcome data (Intensive Care Unit admission and mortality) were collected from all patients until discharge. Viremia was determined longitudinally during hospitalisation, in plasma and serum samples using two commercial and standardised RT-PCR techniques approved for use in diagnosis of SARS-CoV-2. Viral load (copies/mL and log10) was determined with quantitative TaqPath™COVID-19 test. Results SARS-CoV-2 viremia was studied in 57 hospitalised COVID-19 patients. Persistent viremia (PV) was defined as two or more quantifiable viral loads detected in blood samples (plasma/serum) during hospitalisation. PV was detected in 16 (28%) patients. All of them, except for one who rapidly progressed to death, cleared viremia during hospitalisation. Poor clinical outcome occurred in 62.5% of patients with PV, while none of the negative patients or those with sporadic viremia presented this outcome (p<0.0001). Viral load was significantly higher in patients with PV than in those with Sporadic Viremia (p<0.05). Patients presented PV for a short period of time: median time from admission was 5 days (Range=2-12) and 4.5 days (Range=2-8) for plasma and serum samples, respectively. Similar results were obtained with all RT-PCR assays for both types of samples. Conclusions Detection of persistent SARS-CoV-2 viremia, by real time RT-PCR, expressed as viral load over time, could allow identifying hospitalised COVID-19 patients at risk of poor clinical outcome. Highlights Commercial RT-PCR techniques could be used to monitor SARS-CoV-2 viremia kinetics. SARS-CoV-2 persistent viremia is related with poor outcome in COVID-19 patient. SARS-Cov-2 viremia kinetics could be used as a biomarker of poor prognosis. Plasma samples are the best choice for analysis of SARS-CoV-2 viremia kinetics.