Does Nirmatrelvir/Ritonavir Influence the Immune Response Against SARS-CoV-2 Independently From Rebound?

The study examined the impact of Nirmatrelvir/Ritonavir (NM/r) treatment on the immune response to SARS-CoV-2, using three cases of COVID-19 rebound and two control groups (one treated with NM/r without rebound, and one untreated). It was found that patients treated with NM/r had lower levels of anti-spike IgG, suggesting a less robust immune response compared to untreated subjects. This could be due to NM/r's ability to reduce viral load, potentially decreasing the adaptive immune response after exposure to the virus. However, this did not seem to influence the incidence of rebound. Differences in cytokine profiles were also observed between NM/r-treated and untreated patients. The study concluded that the clinical relevance of these observations needs further investigation in larger populations, and future research should focus on characterizing the evolution of the immune response after SARS-CoV-2 infection in patients treated or untreated with NM/r.