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. 2025 Sep 8;12(9):ofaf542.
doi: 10.1093/ofid/ofaf542. eCollection 2025 Sep.

Rapid Elimination of Culturable SARS-CoV-2 With Intramuscular or Intravenous Administration of Antiviral Monoclonal Antibody Therapy

Rinki Deo  1 , Manish C Choudhary  1 , Owen T Glover  2 , Rachel Bender Ignacio  3   4 , Julie Boucau  2 , Kara W Chew  5 , Carlee Moser  6 , Judith S Currier  5 , Joseph J Eron  7 , Arzhang Cyrus Javan  8 , Mark J Giganti  6 , Evgenia Aga  6 , Michael Gibbs  9 , Taylor Cohen  10 , Katie Streicher  10 , Karina Soboleva  10 , Courtney V Fletcher  11 , Eric S Daar  12 , Alexander L Greninger  3 , Robert W Coombs  3 , William Fischer  7 , Michael D Hughes  6 , Davey Smith  13 , David Alain Wohl  7 , Amy K Barczak  2   14 , Jonathan Z Li  1
Affiliations

Rapid Elimination of Culturable SARS-CoV-2 With Intramuscular or Intravenous Administration of Antiviral Monoclonal Antibody Therapy

Rinki Deo et al. Open Forum Infect Dis. .

Abstract

We evaluated intramuscular (IM) versus intravenous (IV) administration of tixagevimab/cilgavimab in early COVID-19. Both routes achieved rapid elimination of culturable virus and minimal emergence of resistance. These results support IM delivery as a viable alternative to IV, with important implications for scalable deployment in future viral pandemics.

Keywords: SARS-CoV-2; intramuscular administration; monoclonal antibodies; tixagevimab/cilgavimab; viral culture conversion.

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Conflict of interest statement

Potential conflicts of interest. J. Z. L. has consulted for AbbVie, Merck, Imunon, and Mallinckrodt. E. S. D. research support from Gilead, ViiV and consultant for Gilead, ViiV, Merck and Theratechnologies. M. J. G. has received support research support from Viiv Healthcare paid to institution. R. B. I. has consulted for AbbVie and receives funding for research from Viiv through her institution, unrelated to this work. J. J. E. receives research support from Gilead and is a consultant to Gilead Sciences and Merck. M. G. work for Vaccines and Immunotherapies, AstraZeneca, Cambridge, UK. T. C., K. Streicher, and K. Soboleva work for Vaccines and Immune Therapies, AstraZeneca, Gaithersburg, USA. No other conflicts reported.

Figures

Figure 1.
Figure 1.
A, Quantitative anterior nasal viral loads (dots) and proportion of participants with culturable SARS-CoV-2 (shaded bars) over time after tixagevimab/cilgavimab (T/C) or placebo administration in N = 24 participants (N = 8 per group) with baseline viral load >106 SARS-CoV-2 RNA copies/ml. B, Time to culture conversion was estimated using the Kaplan–Meier method, and differences between groups were assessed using the log-rank test. C, Frequency of emergent spike resistance mutations in IM (N = 98) and IV (N = 54) T/C versus respective placebo arms (N = 111 for IM, N = 50 for IV). D, Detection of any spike gene polymorphisms in post-treatment samples from the same set of participants as panel C (IM: N = 98, placebo: N = 111; IV: N = 54, placebo: N = 50).
See this image and copyright information in PMC

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