Sustained cell-mediated but not humoral responses in rituximab-treated rheumatic patients after vaccination against SARS-CoV-2.

OBJECTIVES: B cell depleting monoclonal antibodies are associated with increased COVID-19 severity and impaired immune response to vaccination. We aimed to assess the humoral and cell mediated (CMI) immune response after SARS-CoV-2 vaccination in rituximab (RTX)-treated rheumatic patients. METHODS: Serum and whole blood samples were collected from rituximab (RTX)-treated rheumatic patients 3-6 months after last vaccination against SARS-CoV-2. Serum was tested by ELISA for quantitative detection of anti-spike SARS-CoV-2 IgG. Cell-mediated variant-specific SARS-CoV-2 immunity (CMI) was assessed by interferon-γ release assay Covi-FERON FIA. Patients were interviewed for breakthrough COVID-19 infection (BTI) 3 months post sampling. RESULTS: Sixty patients were studied after a median (IQR) of 179 (117-221.5) days from last vaccine to sampling. Forty (66.7%) patients had positive Covi-FERON and 23 (38.3%) had detectable anti-spike IgG. Covi-FERON positive patients had lower median RTX cumulative dose [6 (4-10.75) vs 11 (6.75-14.75) grams, (p= 0.019). Patients with positive anti-spike IgG had received fewer RTX cycles [2 (2-4) vs 6 (4-8), p= 0.002) and cumulative dose [4 (3-7) vs 10 (6.25-13) grams, p= 0.002] and had shorter time from last vaccination to sampling [140 (76-199) vs 192 (128-230) days, p= 0.047). Thirty-seven percent were positive only for Covi-FERON and 7% only for anti-spike IgG. Twenty (33.3%) BTI occurred post sampling, exclusively during Omicron variant predominance. The proportion of patients with CMI response against Delta variant was lower in patients who experienced BTI (25% vs 55%, p= 0.03). CONCLUSIONS: Four out of ten RTX-treated vaccinated patients show lasting cell-mediated immune response despite undetectable anti-spike antibodies. Cumulative RTX dose affects both humoral and cell-mediated responses to SARS-CoV-2 vaccines. Cell-mediated immune responses call for attention as a vaccine efficacy marker against SARS-CoV-2.

Insights into CD24 and Exosome Physiology and Potential Role in View of Recent Advances in COVID-19 Therapeutics: A Narrative Review.

Cluster of differentiation (CD) 24, a long-known protein with multifaceted functions, has gained attention as a possible treatment for Coronavirus Disease 19 (COVID-19) due to its known anti-inflammatory action. Extracellular vesicles (EVs), such as exosomes and microvesicles, may serve as candidate drug delivery platforms for novel therapeutic approaches in COVID-19 and various other diseases due to their unique characteristics. In the current review, we describe the physiology of CD24 and EVs and try to elucidate their role, both independently and as a combination, in COVID-19 therapeutics. CD24 may act as an important immune regulator in diseases with complex physiologies characterized by excessive inflammation. Very recent data outline a possible therapeutic role not only in COVID-19 but also in other similar disease states, e.g., acute respiratory distress syndrome (ARDS) and sepsis where immune dysregulation plays a key pathophysiologic role. On the other hand, CD24, as well as other therapeutic molecules, can be administered with the use of exosomes, exploiting their unique characteristics to create a novel drug delivery platform as outlined in recent clinical efforts. The implications for human therapeutics in general are huge with regard to pharmacodynamics, pharmacokinetics, safety, and efficacy that will be further elucidated in future randomized controlled trials (RCTs).

Real-Life Effectiveness and Safety of Baricitinib as Adjunctive to Standard-of-Care Treatment in Hospitalized Patients With Severe Coronavirus Disease 2019.

BACKGROUND: Therapeutic options for hospitalized patients with severe coronavirus disease 2019 (sCOVID-19) are limited. Preliminary data have shown promising results with baricitinib, but real-life experience is lacking. We assessed the safety and effectiveness of add-on baricitinib to standard-of-care (SOC) including dexamethasone in hospitalized patients with sCOVID-19. METHODS: This study is a 2-center, observational, retrospective cohort study of patients with sCOVID-19, comparing outcomes and serious events between patients treated with SOC versus those treated with SOC and baricitinib combination. RESULTS: We included 369 patients with sCOVID-19 (males 66.1%; mean age 65.2 years; median symptom duration 6 days). The SOC was administered in 47.7% and combination in 52.3%. Patients treated with the combination reached the composite outcome (intensive care unit [ICU] admission or death) less frequently compared with SOC (22.3% vs 36.9%, P = .002). Mortality rate was lower with the combination in the total cohort (14.7% vs 26.6%, P = .005), and ICU admission was lower in patients with severe acute respiratory distress syndrome (29.7% vs 44.8%, P = .03). By multivariable analysis, age (odds ratio [OR] = 1.82, 95% confidence interval [CI] = 1.36-2.44, per 10-year increase), partial pressure of oxygen/fraction of inspired oxygen ratio (OR = 0.60, 95% CI = .52-0.68, per 10 units increase), and use of high-flow nasal cannula (OR = 0.34; 95% CI, .16-0.74) were associated with the composite outcome, whereas baricitinib use was marginally not associated with the composite outcome (OR = 0.52; 95% CI, .26-1.03). However, baricitinib use was found to be significant after inverse-probability weighted regression (OR = 0.93; 95% CI, .87-0.99). No difference in serious events was noted between treatment groups. CONCLUSIONS: In real-life settings, addition of baricitinib to SOC in patients hospitalized with sCOVID-19 is associated with decreased mortality without concerning safety signals.

Vaccination Hesitancy among Health-Care-Workers in Academic Hospitals Is Associated with a 12-Fold Increase in the Risk of COVID-19 Infection: A Nine-Month Greek Cohort Study.

Health-Care-Workers (HCWs) are considered at high risk for SARS-CoV-2 infection. We sought to compare rates and severity of Coronavirus disease 2019 (COVID-19) among vaccinated and unvaccinated HCWs conducting a retrospective cohort study in two tertiary Academic Hospitals, namely Laiko and Attikon, in Athens, Greece. Vaccinated by BNT162b2 Pfizer-BioNTech COVID-19 mRNA vaccine and unvaccinated HCWs were included and data were collected between 1 January 2021 and 15 September 2021. Overall, 2921 of 3219 HCWs without a history of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection were fully vaccinated during the study period (90.7% at each Hospital). Demographic characteristics were comparable between 102/2921 (3.5%) vaccinated and 88/298 (29.5%) unvaccinated HCWs with COVID-19, although age and occupation differed significantly. None were in need of hospital admission in the vaccinated Group, whereas in the unvaccinated Group 4/88 (4.5%) were hospitalized and one (1.1%) died. Multivariable logistic regression analysis revealed that lack of vaccination was an independent risk factor for COVID-19 with an odds ratio 11.54 (95% CI: 10.75-12.40). Vaccination hesitancy among HCWs resulted to highly increased COVID-19 rates; almost one in three unvaccinated HCWs was SARS-CoV-2 infected during the 9-month period. The absolute need of vaccination of HCWs, including boosting dose, is highlighted. Evidence should be used appropriately to overcome any hesitancy.

Increased influenza vaccination rates in patients with autoimmune rheumatic diseases during the Covid-19 pandemic: a cross-sectional study.

To assess non-compliance and potential changes in seasonal flu vaccination coverage before and during the Covid-19 pandemic in patients with autoimmune rheumatic diseases (ARDs). Consecutive patients with ARDs followed-up in 2 tertiary hospitals were telephone-interviewed (December 12-30, 2020) regarding seasonal flu vaccination during the 2019/20 and 2020/21 time periods. Self-reported disease flares that occurred after flu vaccination, as well as reasons for non-vaccination were recorded. One thousand fifteen patients were included. The rate of flu vaccination increased from 76% before to 83% during the COVID-19 pandemic (p = 0.0001). The rate of self-reported disease flares was < 1% among vaccinated patients. Reasons for not vaccination in both periods, respectively, included: 'was not recommended by their rheumatologists' (35.0vs.12.2%, p < 0.0001), 'did not feel that they would have any benefit' (36.9 vs. 32.6%), felt unsafe to do so (27.5 vs. 30.2%), or other reasons (18.9 vs. 23.8%). By multivariate analysis, age [OR = 1.03 (95% CI 1.02-1.04)] vs. [1.04 (95% CI 1.02-1.05)] and treatment with biologics [OR = 1.66 (95% CI 1.22-2.24) vs. [1.68 (95% CI 1.19-2.38)] were independent factors associated with vaccination in both periods. These findings, although are temporally encouraging, emphasize the need for continuous campaigns aiming at increasing patients' and physicians' awareness about the benefits of vaccination.