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. 2023 Feb 8;76(3):e530-e532.
doi: 10.1093/cid/ciac496.

Virologic and Immunologic Characterization of Coronavirus Disease 2019 Recrudescence After Nirmatrelvir/Ritonavir Treatment

Aaron F Carlin  1 , Alex E Clark  1 , Antoine Chaillon  1 , Aaron F Garretson  1 , William Bray  2 , Magali Porrachia  1 , AsherLev T Santos  3 , Tariq M Rana  4 , Davey M Smith  1   5
Affiliations

Virologic and Immunologic Characterization of Coronavirus Disease 2019 Recrudescence After Nirmatrelvir/Ritonavir Treatment

Aaron F Carlin et al. Clin Infect Dis. .

Abstract

We isolated a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) BA.2 variant from a person with coronavirus disease 2019 recrudescence after nirmatrelvir/ritonavir treatment. Antiviral sensitivity and neutralizing antibody testing were performed with both parental SARS-CoV-2 and multiple variants of concern. We found that neither nirmatrelvir resistance nor absence of neutralizing immunity was a likely cause of the recrudescence.

Keywords: COVID-19; COVID-19 recrudescence; Omicron; nirmatrelvir; treatment rebound.

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Conflict of interest statement

Potential conflicts of interest. A. F. C. has received contract payments from Nurix Therapeutics and has options in Covicept Therapeutics. D. M. S. has served as a consultant for Bayer Healthcare, Kiadis Pharmaceuticals, and Signant Health, and has equity stake in Vx Biosciences, Model Medicines, Linear Therapies, and FluxErgy. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.

Figures

Figure 1.
Figure 1.
Comparison of antiviral activity (A) and neutralization (B) against BA.2 PRSD01 after nirmatrelvir combined with ritonavir recrudescence. Dose response curves, half-maximal inhibitory concentrations, and half-maximal authentic virus-neutralizing antibody concentrations show the averages ± standard deviation from 2 independent experiments with 2 biological replicates. Abbreviations: Ab, antibody; Ctl, control; IC50, half-maximal inhibitory concentration; NM/r, nirmatrelvir combined with ritonavir; NT50, half-maximal authentic virus-neutralizing antibody concentration.
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