Clinical Trial to Evaluate the Safety and Immunogenicity of a Priming Regimen of 426c.Mod.Core-C4b Followed by HxB2.WT.Core-C4b Boosts, Both Adjuvanted With 3M-052 AF + Alum, in Adult Participants Without HIV and in Overall Good Health

This is a clinical trial testing a new experimental HIV vaccine approach. It tests whether giving a specific "priming" vaccine followed by multiple "booster" shots (all using a special adjuvant to strengthen immune response) can generate protective antibodies against HIV in healthy adults who do not have HIV. **You may be eligible if...** - You are between 18 and 55 years old - You are HIV-negative and in generally good health - You are available for all clinic follow-up visits and willing to undergo a blood collection procedure (leukapheresis) - You are not currently enrolled in another investigational drug study (or can get approval) **You may NOT be eligible if...** - You have HIV or a serious chronic illness - You are pregnant or not using adequate contraception - You have a condition or risk factor that the study team determines makes participation unsafe - You are already taking an investigational drug in another trial Talk to your doctor to see if this trial is right for you.