Clinical Data Cohorts of younger adults (n=300) and older adults (n=300) in Phase 2 study fully enrolledCohorts of older adults (ages 56-70, n=30) and elderly adults (ages 71 and above, n=30) in NIH-led Phase 1 study completed enrollment; results expected to be published once availablePivotal Phase 3 study expected to begin in July; manufacture of vaccine required to start Phase 3 study completed