Long COVID After Bamlanivimab Treatment

Abstract Background Prospective evaluations of long COVID in outpatients with coronavirus disease 2019 (COVID-19) are lacking. We aimed to determine the frequency and predictors of long COVID after treatment with the monoclonal antibody bamlanivimab in ACTIV-2/A5401. Methods Data were analyzed from participants who received bamlanivimab 700 mg in ACTIV-2 from October 2020 to February 2021. Long COVID was defined as the presence of self-assessed COVID symptoms at week 24. Self-assessed return to pre-COVID health was also examined. Associations were assessed by regression models. Results Among 506 participants, median age was 51 years. Half were female, 5% Black/African American, and 36% Hispanic/Latino. At 24 weeks, 18% reported long COVID and 15% had not returned to pre-COVID health. Smoking (adjusted risk ratio [aRR], 2.41 [95% confidence interval {CI}, 1.34– 4.32]), female sex (aRR, 1.91 [95% CI, 1.28–2.85]), non-Hispanic ethnicity (aRR, 1.92 [95% CI, 1.19–3.13]), and presence of symptoms 22–28 days posttreatment (aRR, 2.70 [95% CI, 1.63–4.46]) were associated with long COVID, but nasal severe acute respiratory syndrome coronavirus 2 RNA was not. Conclusions Long COVID occurred despite early, effective monoclonal antibody therapy and was associated with smoking, female sex, and non-Hispanic ethnicity, but not viral burden. The strong association between symptoms 22–28 days after treatment and long COVID suggests that processes of long COVID start early and may need early intervention. Clinical Trials Registration NCT04518410.