Spike-specific T-cell responses in patients with COVID-19 successfully treated with neutralizing monoclonal antibodies against SARS-CoV-2

Objectives: Neutralizing monoclonal antibodies (moAbs) improves clinical outcomes in patients with COVID-19 when administered during the initial days of infection. The action of moAbs may impair the generation or maintenance of effective immune memory, similar to that demonstrated in other viral diseases. We aimed to evaluate short-term memory T-cell responses in patients effectively treated with bamlanivimab/etesevimab, casirivimab/imdevimab, or sotrovimab (SOT). Methods: Spike (S)-specific T-cell responses were analyzed in 23 patients with COVID-19 (vaccinated or unvaccinated) before and after a median of 50 (range: 28-93) days from moAb treatment, compared with 11 vaccinated healthy controls. T-cell responses were measured by interferon-γ-enzyme-linked immunospot and flow cytometric activation-induced marker assay. Results: No statistically significant difference in S-specific T-cell responses was observed between patients treated with moAb and vaccinated healthy controls. Bamlanivimab/etesevimab and casirivimab/imdevimab groups showed significant increases in cellular responses in paired baseline/postrecovery series, as well as vaccinated patients receiving SOT. In contrast, unvaccinated patients prescribed SOT presented no statistically significant increases in T-cell-responses, suggesting diverse impacts of different moAbs on the evolution of S-specific T-cell responses in vaccinated and unvaccinated patients. Conclusion: The moAbs did not hinder short-term memory S-specific T-cell responses in the overall group of patients; however, differences among moAbs must be further investigated both in vaccinated and unvaccinated individuals.