Invivyd reported Phase 3 LIBERTY results showing its low-dose monoclonal antibody VYD2311 was better tolerated than Pfizer’s Comirnaty mRNA vaccine in a head-to-head safety and tolerability comparison. After six days, 57% of participants in the VYD2311 group reported typical vaccine-like systemic or injection-site side effects (headache, chills, fatigue or pain at the injection site), versus 91% in the Comirnaty arm; the difference was statistically significant. The study also indicated improved tolerability at 56 days and reported VYD2311 could be combined safely with Comirnaty. The finding supports Invivyd’s approach of offering vaccine-like protection without the same “vaccine” framing, though efficacy against infection would remain a separate question for later reporting.