Phase 1 Trial to Assess the Safety and Immunogenicity of an Inactivated, Adjuvanted Whole Zika Virus Vaccine Candidate (VLA1601) in Healthy Adults

Key Inclusion Criteria: * 18 to 49 years of age * BMI of ≥18.5 and \<30 kg/m2 * generally healthy as determined by the investigator's clinical judgement based on medical history, physical examination, and screening laboratory tests. * If trial participant is of childbearing potential: negative pregnancy test; employ adequate birth control measures up to Day 208. * Male participant agrees to employ adequate birth control measures up to 90 days after last vaccination. Key Exclusion Criteria: Participant * has a known history of the following flavivirus infection: Zika Virus (ZIKV), Japanese Encephalitis Virus (JEV), Dengue Virus (DENV), Yellow Fever Virus (YFV), West-Nile Virus (WNV), or Tick-Borne Encephalitis Virus (TBEV). * received or has plans to receive a licensed or investigational flavivirus vaccine during the course of the trial. * travelled within 4 weeks prior to trial enrollment or has plans to travel to areas (including within the US) with Zika virus (ZIKV), Japanese Encephalitis Virus (JEV), Dengue Virus (DENV) or Yellow Fever Virus (YFV) active transmission/circulation during the course of the trial . * received active or passive immunization within 4 weeks prior or planned to get such vaccination after any trial-vaccination. * presents with clinically significant abnormal laboratory values, as determined by the investigator. * tests positive for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV). * has history of significant cardiovascular, respiratory (including asthma), metabolic, neurological (including Guillain-Barre syndrome \[GBS\]), psychiatric, hepatic, rheumatic, autoimmune, hematological, gastrointestinal, or renal disorder. * with known or suspected defect of the immune system that would prevent an immune response to the vaccine. * received immuno-suppressive therapy within 4 weeks prior to first vaccination. Radiation therapy or immunosuppressive cytotoxic drugs/ monoclonal antibodies in the previous 3 years. * with a history of severe hypersensitivity reactions or anaphylaxis. * with a history of any vaccine related contraindicating event . * with acute febrile infections within two weeks prior to vaccination in this trial. * donated blood within 4 weeks or received blood-derived products (e.g. plasma) within 12 weeks prior to vaccination in this trial or plans to donate blood or use blood products during the course of the trial. * has a rash, dermatological condition or tattoos that would, in the opinion of the investigator, interfere with injection site reaction rating. * presents with clinical conditions representing a contraindication to intramuscular vaccination and blood draws. * is currently enrolled (ICF signed) or has participated in another clinical trial involving an investigational medicinal product (IMP) or device within 4 weeks prior to trial enrollment or is scheduled to participate in another clinical trial involving an IMP or investigational device during the course of this trial. * has a known or suspected problem with alcohol or drug abuse