A Study to Evaluate the Safety of the Respiratory Syncytial Virus Vaccine MEDI7510 in Older Adults

A phase 1a, first time in human, double-blind, randomized, placebo-controlled, cohort escalation study evaluating the safety and tolerability of a single ascending intramuscular dose of RSV sF or MEDI7510 or placebo. Approximately 146 participants will be enrolled at 3 US study centers and randomized in a 5:1 ratio by cohort as described below: Cohort 1: RSV sF 20 microgram (mcg) (n=20) or placebo (n=4) Cohort 1a: MEDI7510 (20 mcg RSV sF with 2.5 mcg glucopyranosyl lipid A (GLA) + 2% weight per volume stable emulsion (n=20) or placebo (n=4) Cohort 2: RSV sF 50 mcg (n=20) or placebo (n=4) Cohort 2a: MEDI7510 (50 mcg RSV sF with 2.5 mcg glucopyranosyl lipid A (GLA) + 2% weight per volume stable emulsion (n=20) or placebo (n=4) Cohort 3: 80 mcg RSV sF (n=20) or placebo (n=4) Cohort 3a: MEDI7510 (80 mcg RSV sF with 2.5 mcg glucopyranosyl lipid A (GLA) + 2% weight per volume stable emulsion (n=20) or placebo (n=4)