Go to The Journal of Clinical Investigation
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Journal stats
  • Publication ethics
  • Publication alerts by email
  • Transfers
  • Advertising
  • Job board
  • Contact
  • Physician-Scientist Development
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Immunology
    • Metabolism
    • Nephrology
    • Oncology
    • Pulmonology
    • All ...
  • Videos
  • Collections
    • In-Press Preview
    • Resource and Technical Advances
    • Clinical Research and Public Health
    • Research Letters
    • Editorials
    • Perspectives
    • Physician-Scientist Development
    • Reviews
    • Top read articles

  • Current issue
  • Past issues
  • Specialties
  • In-Press Preview
  • Resource and Technical Advances
  • Clinical Research and Public Health
  • Research Letters
  • Editorials
  • Perspectives
  • Physician-Scientist Development
  • Reviews
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Journal stats
  • Publication ethics
  • Publication alerts by email
  • Transfers
  • Advertising
  • Job board
  • Contact
Bamlanivimab therapy for acute COVID-19 does not blunt SARS-CoV-2–specific memory T cell responses
Sydney I. Ramirez, Alba Grifoni, Daniela Weiskopf, Urvi M. Parikh, Amy Heaps, Farhoud Faraji, Scott F. Sieg, Justin Ritz, Carlee Moser, Joseph J. Eron, Judith S. Currier, Paul Klekotka, Alessandro Sette, David A. Wohl, Eric S. Daar, Michael D. Hughes, Kara W. Chew, Davey M. Smith, Shane Crotty, for the Accelerating COVID-19 Therapeutic Interventions and Vaccines–2/A5401 (ACTIV-2/A5401) Study Team
Sydney I. Ramirez, Alba Grifoni, Daniela Weiskopf, Urvi M. Parikh, Amy Heaps, Farhoud Faraji, Scott F. Sieg, Justin Ritz, Carlee Moser, Joseph J. Eron, Judith S. Currier, Paul Klekotka, Alessandro Sette, David A. Wohl, Eric S. Daar, Michael D. Hughes, Kara W. Chew, Davey M. Smith, Shane Crotty, for the Accelerating COVID-19 Therapeutic Interventions and Vaccines–2/A5401 (ACTIV-2/A5401) Study Team
View: Text | PDF
Research Article COVID-19 Immunology

Bamlanivimab therapy for acute COVID-19 does not blunt SARS-CoV-2–specific memory T cell responses

  • Text
  • PDF
Abstract

Despite the widespread use of SARS-CoV-2–specific monoclonal antibody (mAb) therapy for the treatment of acute COVID-19, the impact of this therapy on the development of SARS-CoV-2–specific T cell responses has been unknown, resulting in uncertainty as to whether anti–SARS-CoV-2 mAb administration may result in failure to generate immune memory. Alternatively, it has been suggested that SARS-CoV-2–specific mAb may enhance adaptive immunity to SARS-CoV-2 via a “vaccinal effect.” Bamlanivimab (Eli Lilly and Company) is a recombinant human IgG1 that was granted FDA emergency use authorization for the treatment of mild to moderate COVID-19 in those at high risk for progression to severe disease. Here, we compared SARS-CoV-2–specific CD4+ and CD8+ T cell responses of 95 individuals from the ACTIV-2/A5401 clinical trial 28 days after treatment with bamlanivimab versus placebo. SARS-CoV-2–specific T cell responses were evaluated using activation-induced marker assays in conjunction with intracellular cytokine staining. We demonstrate that most individuals with acute COVID-19 developed SARS-CoV-2–specific T cell responses. Overall, our findings suggest that the quantity and quality of SARS-CoV-2–specific T cell memory were not diminished in individuals who received bamlanivimab for acute COVID-19. Receipt of bamlanivimab during acute COVID-19 neither diminished nor enhanced SARS-CoV-2–specific cellular immunity.

Authors

Sydney I. Ramirez, Alba Grifoni, Daniela Weiskopf, Urvi M. Parikh, Amy Heaps, Farhoud Faraji, Scott F. Sieg, Justin Ritz, Carlee Moser, Joseph J. Eron, Judith S. Currier, Paul Klekotka, Alessandro Sette, David A. Wohl, Eric S. Daar, Michael D. Hughes, Kara W. Chew, Davey M. Smith, Shane Crotty, for the Accelerating COVID-19 Therapeutic Interventions and Vaccines–2/A5401 (ACTIV-2/A5401) Study Team

×

Figure 7

SARS-CoV-2–specific baseline IgG titers and seropositivity are similar among treatment and placebo groups, and non-RBD IgG titers and seropositivity rates at day 28 are similar among treatment and placebo group participants.

Options: View larger image (or click on image) Download as PowerPoint
SARS-CoV-2–specific baseline IgG titers and seropositivity are similar a...
(A–C) Baseline IgG titers for ancestral SARS-CoV-2 N (in A), S2 (in B), and RBD (in C) at study entry (day 0) in individuals who received bamlanivimab (blue circles) versus placebo (gray circles) in AU/mL. (D–F) Day 28 IgG titers for ancestral SARS-CoV-2 N (in D), S2 (in E), and RBD (in F) in treatment (blue circles) and placebo (gray circles) groups. Dotted black line indicates lower LOQ of detection (titer) for Bio-Plex (N, S2, RBD) serologic assays. Dotted red line indicates cutoff for positivity for Bio-Plex assays; titer results were generated using a standard curve generated by standards provided by the manufacturer (out-of-range titers were excluded from analyses). MFI-based positivity was set based on results generated using prepandemic, SARS-CoV-2–uninfected control samples. See also Supplemental Figure 7. GMT, geometric mean titer.

Copyright © 2026 American Society for Clinical Investigation
ISSN 2379-3708

Sign up for email alerts