Clinical Outcomes of Monoclonal Antibody Therapy During a COVID-19 Outbreak in a Skilled Nursing Facility

Arizona, 2021

Ariella P. Dale PhD, MPH; Matthew J. Hudson MD, MPH; Darunee Armenta RN; Heather Friebus RD, LNHA; Katherine D. Ellingson PhD; Kat Davis MPH; Theresa Cullen MD, MS; Shane Brady MPH; Kenneth K. Komatsu MPH; Nimalie D. Stone MD, MS; Timothy M. Uyeki MD, MPH; Kara Jacobs Slifka MD, MPH; Carlos M. Pérez-Vélez MD; Amelia A. Keaton MD, MS


J Am Geriatr Soc. 2022;70(4):960-967. 

In This Article

Abstract and Introduction


Background: Adult residents of skilled nursing facilities (SNF) have experienced high morbidity and mortality from SARS-CoV-2 infection and are at increased risk for severe COVID-19 disease. Use of monoclonal antibody (mAb) treatment improves clinical outcomes among high-risk outpatients with mild-to-moderate COVID-19, but information on mAb effectiveness in SNF residents with COVID-19 is limited. We assessed outcomes in SNF residents with mild-to-moderate COVID-19 associated with an outbreak in Arizona during January–February 2021 that did and did not receive a mAb.

Methods: Medical records were reviewed to describe the effect of bamlanivimab therapy on COVID-19 mortality. Secondary outcomes included referral to an acute care setting and escalation of medical therapies at the SNF (e.g., new oxygen requirements). Residents treated with bamlanivimab were compared to residents who were eligible for treatment under the FDA's Emergency Use Authorization (EUA) but were not treated. Multivariable logistic regression was used to determine association between outcomes and treatment status.

Results: Seventy-five residents identified with COVID-19 during this outbreak met eligibility for mAb treatment, of whom 56 received bamlanivimab. Treated and untreated groups were similar in age and comorbidities associated with increased risk of severe COVID-19 disease. Treatment with bamlanivimab was associated with reduced 21-day mortality (adjusted OR = 0.06; 95% CI: 0.01, 0.39) and lower odds of initiating oxygen therapy (adjusted OR = 0.07; 95% CI: 0.02, 0.34). Referrals to acute care were not significantly different between treated and untreated residents.

Conclusions: mAb therapy was successfully administered to SNF residents with COVID-19 in a large outbreak setting. Treatment with bamlanivimab reduced 21-day mortality and reduced initiation of oxygen therapy. As the COVID-19 pandemic evolves and newer immunotherapies gain FDA authorization, more studies of the effectiveness of mAb therapies for treating emerging SARS-CoV-2 variants of concern in high-risk congregate settings are needed.


The ongoing coronavirus 19 (COVID-19) pandemic has resulted in unprecedented morbidity and mortality worldwide, with a disproportionate number of illnesses and deaths occurring among residents of skilled nursing and long term care facilities (LTCFs).[1–3] Since November 2020, the Food and Drug Administration (FDA) has granted Emergency Use Authorization (EUA) for multiple monoclonal antibody (mAb) therapies for the treatment of mild-to-moderate COVID-19 in non-hospitalized persons at high risk of severe disease.[4] Limited data from clinical trials and real-world effectiveness studies suggest that use mAbs reduces emergency department visits and hospitalization rates among those treated.[5] However, mAb use has largely been reported in outpatient, non-congregate settings; and the effectiveness and feasibility of mAb therapies among older and medically vulnerable populations during COVID-19 outbreaks in LTCFs is limited.[6] We describe the use of the mAb bamlanivimab for treatment of mild-to-moderate COVID-19 during an outbreak in residents of a large SNF in Arizona from January to February 2021.