A Real-World Assessment of Unvaccinated And Vaccinated Patients With Coronavirus Disease 2019 (COVID-19) Treated With Monoclonal Antibodies During The Delta Wave

Abstract

Background: Monoclonal antibodies (mAb) prevent COVID-19 progression during early disease presentation. We aimed to compare the mAb treatment outcomes among vaccinated and unvaccinated patients during Delta wave and assess the feasibility of implementing stricter eligibility criteria given mAb scarcity in New York City.Methods: We conducted a retrospective observational study of casirivimab/imdevimab recipients with mild-to-moderate COVID-19 infection in an emergency department or outpatient infusion center (July 1 – August 20, 2021). The outcome was all-cause hospital admission within 30 days post-treatment between vaccinated vs. unvaccinated patients during Delta surge in the Bronx, NY. Results: A total of 250 patients received casirivimab/imdevimab (162 unvaccinated vs. 88 vaccinated). The median age was 39 years for unvaccinated patients, and 52 years for vaccinated patients (p<0.0001). The median number of EUA criteria met was 1 for unvaccinated and 2 for vaccinated patients (p<0.0001). Overall, 6% (15/250) of patients were admitted within 30 days post-treatment. Eleven unvaccinated patients (7%) were admitted (all-cause) within 30-days compared to 4 (5%) of vaccinated patients (p=0.48).Conclusions: All-cause 30-day admission was not statistically different between vaccinated and unvaccinated patients. With limited federal allocation of therapies, programs must prioritize patients at highest risk of hospitalization and death regardless of vaccination status.

Real-world effect of casirivimab and imdevimab cocktail in patients infected with SARS-CoV-2 delta and omicron variants

“…Casirivimab and imdevimab cocktail treatment was associated with lower rates of hospitalization among 403 vaccinated and unvaccinated patients [35]. The mAb recipients have shown a similar all cause 30 day admission rate independent of vaccination status, supporting FDA in vitro evidence suggesting maintained action of casirivimab and imdevimab antibodies against delta VOC [22,26]. In our observations, 47% of the patients with delta variant and 94% of patients with omicron variant were vaccinated.…”

“…The use of antibody cocktail has piqued interest since the start of the COVID-19 pandemic, due to decreased virus replication and mortality owing to its antibodies neutralizing effect [1,21]. Antibody cocktail is reported to prevent COVID-19 progression during early disease presentation [22]. Two most common monoclonal antibodies currently used are casirivimab/imdevimab and sotrovimab [23].…”

“…The casirivimab and imdevimab antibody cocktail has been administered to more than 16,000 people in clinical trials which included both hospitalized and non-hospitalized patients [26]. The cocktail's capacity to preserve effectiveness against delta VOC has been demonstrated in COVID-19 patients [1,22,27]. Recent in vitro investigations however indicated that the omicron VOC escapes neutralization by imdevimab and casirivimab antibody cocktail [28][29].…”