Saturday, August 1, 2026
Moderna's norovirus vaccine misses Phase 3 interim efficacy bar
Moderna disclosed on July 31, 2026 that the Phase 3 interim analysis of its norovirus vaccine candidate mRNA-1403 (the ~38,000-participant NOVA 301 study) did not meet the statistical threshold for early success. The company is enrolling an additional cohort after case accrual came in slower than expected across two Northern Hemisphere seasons, pushing a definitive efficacy readout to 2027-2028 while it maintains its full-year revenue growth guidance.