A Study to Evaluate the Safety and Immunogenicity of a Single Dose of H1ssF-3928 mRNA-LNP in Healthy Adults

Occurrence of any adverse events of special interest (AESIs) with VRC H1ssF_3928 mRNA-LNP vaccine.,Occurrence of any influenza-like illnesses (ILIs) with VRC H1ssF_3928 mRNA-LNP vaccine.,Occurrence of any medically attended adverse events (MAAEs) with VRC H1ssF_3928 mRNA-LNP vaccine.,Occurrence of any new-onset chronic medical conditions (NOCMCs) with VRC H1ssF_3928 mRNA-LNP vaccine.,Occurrence of any serious adverse events (SAEs) with VRC H1ssF_3928 mRNA-LNP vaccine.,Occurrence of any unsolicited adverse events (AEs) with VRC H1ssF_3928 mRNA-LNP vaccine.,Occurrence of clinical laboratory adverse events (AEs) with VRC H1ssF_3928 mRNA-LNP vaccine.,Occurrence of solicited reactogenicity adverse events (AEs) with VRC H1ssF_3928 mRNA-LNP vaccine.

This is a Phase 1, single-site, open-label, comparator-controlled dose escalating study of an
 intramuscularly (IM) administered mRNA-LNP vaccine encoding for (Vaccine Research Center) VRC
 H1ssF 3928 of up to 50 healthy adult volunteers aged 18 to 49 years, inclusive. This study is
 designed to assess the safety and immunogenicity of one dose of H1ssF 3928 mRNA Vaccine.
 Eligible participants will be sequentially enrolled into dosing groups (10 mcg, 25 mcg, and
 50 mcg, selected optimal dose) to receive the H1ssF 3928 mRNA Vaccine at the specified dose.
 A separate group of 10 participants will receive licensed quadrivalent influenza vaccine
 (IIV4). Subjects receiving IIV4 will be followed for safety but only their immune responses
 will be compared to those of participants receiving H1ssF 3928 mRNA Vaccine. Dosing of H1ssF
 3928 mRNA Vaccine will commence at the lowest dose (10 mcg) and only escalate to the next
 highest dose if safety concerns are not identified. Up to ten subjects will be enrolled per
 dosing cohort. Reactogenicity and adverse event (AE) information through Day 7 and clinical
 laboratory results through Day 8 from the first three dosing groups will guide the selection
 of an optimal dose group to include 10 subjects who will receive the optimal dose of
 mRNA-LNP. The primary objective of this study is to assess the safety of a single dose of VRC
 H1ssF 3928 mRNA-LNP vaccine administered IM in healthy adults, 18-49 yrs, at doses of 10 mcg,
 25 mcg, and 50 mcg.