The Sars-CoV-2 circulating in France as of December 2022 is the BQ.1.1 sublineage of Omicron variant BA.5 (1). To what degree does this affect the possible benefits of treatment with Sars-CoV-2-specif ic monoclonal antibodies or the combination of nirmatrelvir + ritonavir (Paxlovid°)? A few studies have provided some answers to this question. In vitro: monoclonal antibodies have no op barely any activity. A Japanese team tested several drugs in vitro for their neutralising activity against the BQ.1.1 sublineage of Omicron variant BA.5 (2). Among the monoclonal antibodies targeting the spike protein of Sars-CoV-2, and known to have marked in-vitro neutralising activity against an ancestral strain of this virus, several had no or barely any effect on this sublineage: the combinations of tixagevimab + cilgavimab (Evusheld°) and casirivimab + imdevimab (Ronapreve°), and sotrovimab (Xevudy°) (2). They are therefore likely to have greatly reduced clinical efficacy against infections with sublineage BQ.1.1. In contrast, nirmatrelvir, which inhibits a protease essential forviral replication, through a mechanism unrelated to the spike protein mutations that characterise Sars-CoV-2 variants, appeared to have a similar level of in-vitro activity against this sublineage as against an ancestral strain (2,3).
展开▼
