An oral norovirus vaccine tablet was safe and elicited mucosal immunity in older adults in a phase 1b clinical trial

plasmablasts expressing the mucosal-homing marker α4β7. VP1-specific IgA increased in saliva and nasal lining fluid 28 days postvaccination in both age groups and remained above baseline concentrations through 210 days, demonstrating durable mucosal responses. This clinical trial established that oral administration of VXA-G1.1-NN is safe, well tolerated, and induces robust systemic and mucosal immune responses in adults up to 80 years old.