Placebo-Controlled, Randomized Trial of Ensitrelvir (S-217622) for Viral Persistence and Inflammation in People Experiencing Long COVID (PREVAIL-LC)

Henrich et al., NCT06161688, PREVAIL-LC, NCT06161688, Apr 2026

Ensitrelvir for COVID-19

50th treatment shown to reduce risk in July 2023, now with p = 0.036 from 10 studies, recognized in 2 countries.
Lower risk for recovery, cases, and viral clearance.

No treatment is 100% effective.
Protocols combine treatments.

RCT 40 long COVID patients in the USA, showing no significant improvement with ensitrelvir.
Henrich et al., 2 Apr 2026, Double Blind Randomized Controlled Trial, placebo-controlled, USA, preprint, 1 author, trial NCT06161688 (history) (PREVAIL-LC).
Late treatment
is less effective