Casirivimab/imdevimab treatment for outpatient COVID-19 during a SARS-CoV-2 B1.617.2 (Delta) surge at a community hospital

Abstract

Context Vaccination status has been shown to be linked to patient-centered outcomes in those with COVID-19. However, minimal data have explored the relationship between vaccination status and representation rates after receiving monoclonal antibodies (MABs) the Delta strain of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) in a community setting. Objectives The authors sought to determine if there was a difference in patient-centered outcomes between those who were vaccinated and unvaccinated after the administration of casirivimab/imdevimab for mild-to-moderate COVID-19 during the time when the Delta strain was most prevalent. Methods A convenience sample of consecutive adults given casirivimab/imdevimab at either an outpatient infusion center or within the emergency department (ED) were included in analysis. Patient demographics, authorized-use qualifiers from the emergency use authorization (EUA), baseline vital signs at the time of infusion, representation rates to a healthcare provider within the hospital’s network, and any admissions to the hospital following infusion were all collected from the patient’s electronic medical record. Vaccination status was confirmed in both the patient’s electronic medical record and the Arizona State Immunization Information System (ASIIS). Analysis was conducted utilizing descriptive statistics, the Mann–Whitney U test for continuous data, and the chi-squared analysis for nominal data. Results In total, 743 patients were included in the study, with 585 being unvaccinated and 158 being vaccinated at the time of administration. Those in the vaccinated group were more likely to be older (60.0 vs. 55.0 years; p<0.001) and to have a history of diabetes (18.4% vs. 11.3%; p=0.02), hypertension (39.9% vs. 28.5%; p=0.006), immunosuppression (7.0% vs. 1.4%; p<0.001), and chronic kidney disease (7.0% vs. 3.4%; p=0.05). In the entire sample, 105 (14.1%) patients had an unexpected return visit to either the ED or urgent care at 28 days, with 17 (2.3%) requiring hospitalization. Patients who were vaccinated were more likely to represent for care after casirivimab/imdevimab infusion (20.3% vs. 12.5%; p=0.01), but no difference was noted in hospitalization rates between the two groups (18.8% vs. 15.1%; p=0.15). Conclusions MAB therapy with casirivimab/imdevimab for the outpatient treatment of mild-to-moderate COVID-19 was associated with a low rate of hospitalization. However, those who were vaccinated were more likely to present for unexpected return care at either the ED or urgent care within 28 days of the initial infusion.

Differential expression of Type I interferon and inflammatory genes in SARS‐CoV‐2‐infected patients treated with monoclonal antibodies

“…From a clinical point of view, a previous study found that mAbs therapy with casirivimab/imdevimab was associated with a low rate of hospitalization in both vaccinated and unvaccinated individuals. 32 Although IFN-I mRNA expression did not change in our vaccinated patients after mAbs treatment, a relevant number of patients had undetectable SARS-CoV-2 RNA, maybe due to the combined antiviral effect of previous vaccination and mAbs. By contrast, despite the increased IFN-I mRNA expression levels in the unvaccinated group following mAbs treatment, none were negative for SARS-CoV-2-RNA 12 days after the treatment.…”

Retrospective Analysis of Vaccinated and Unvaccinated COVID-19 Patients Treated with Monoclonal Antibodies (mAb) and Their Emergent Needs (RAVEN)

“…In contrast to our study, vaccinated patients were more likely to present to the ED and urgent care within 28 days. However, Keshishian et al examined urgent care presentation and had a longer follow-up period [ 22 ]. Srinivasan et al performed a multi-site retrospective review of 2209 patients treated outpatient with mAb in California over one year.…”

“…While vaccination and mAb are independently associated with reduced hospitalization and all-cause mortality in COVID-19 positive patients, and mAb therapy further decreases the risk of disease progression in vaccinated patients [ 18 , 19 , 20 ], data comparing clinical outcomes in vaccinated and unvaccinated patients treated with mAb is unclear. Studies examining mAb treatment outcomes regarding vaccination status had conflicting results [ 21 , 22 ]. There remains a need to ascertain a difference in response to the mAb therapy between vaccinated and unvaccinated patients.…”

The Promotion of Humoral Immune Responses in Humans via SOCS1-Mediated Th2-Bias Following SARS-CoV-2 Vaccination

“…Although the currently approved vaccines have considerable effectiveness, a number of people still cannot generate sufficient antiviral immune responses following vaccination, resulting in low IgG and neutralizing antibody levels [7,8]. Additionally, the continuous emergence of SARS-CoV-2 mutant strains, especially the Delta mutant strain (B.617.2), poses a serious threat to SARS-CoV-2 vaccine effectiveness, leading to a sharp increase in COVID-19 infection rates across many countries [9,10]. Therefore, studies on the mechanisms underlying the differences in human immune response after vaccination will shed insights into virus pathogenesis and the development of effective preventative therapeutics against both SARS-CoV-2 and influenza viruses [11][12][13][14].…”