To evaluate the efficacy of ensitrelvir in preventing symptomatic Covid-19 in household contacts exposed to SARS-CoV-2 during a phase 3 trial.
Key Findings:
Covid-19 developed by day 10 in 3% of ensitrelvir recipients vs 9% of placebo recipients in the modified intention-to-treat population, indicating a 67% relative risk reduction.
In the intention-to-treat population, Covid-19 developed in 4% of ensitrelvir recipients vs 10% of placebo recipients, corresponding to a 57% relative risk reduction.
Among participants with risk factors for severe illness, Covid-19 developed in 9 of 382 ensitrelvir recipients vs 37 of 374 placebo recipients.
Adverse events occurred in 15% of ensitrelvir recipients and 16% of placebo recipients, with no Covid-19-related hospitalizations or deaths reported.
Interpretation:
The trial suggests that ensitrelvir may effectively reduce the risk of symptomatic Covid-19 in household contacts when administered shortly after exposure, highlighting its potential role in public health strategies.
Limitations:
The study population was highly immune, which may limit generalizability and reflect the current global immunologic landscape.
Lack of data on household size, masking, distancing, and other public health measures may impact the applicability of the findings.
Exclusion of pregnant patients and those with recent SARS-CoV-2 infection or vaccination may limit the understanding of ensitrelvir's efficacy in broader populations.
Conclusion:
The findings indicate the potential effectiveness of ensitrelvir in reducing the risk of illness in unprotected contexts, such as outbreaks in care facilities, underscoring its relevance in current public health discussions.
A year-long LC-MS/MS study suggests wastewater surveillance can reveal shifts in drug consumption linked to public events, weekends, and law enforcement activity
