Patient Inclusion Criteria

1. Subject must sign written informed consent to participate in the trial. 2. Subject is able to understand planned study procedures and demonstrate comprehension of the protocol procedures and knowledge of the study by passing a quiz (assessment of understanding). Subjects must score at least 80% correct on a multiple-choice quiz. If they do not score 80% on the initial quiz, the protocol information will be reviewed with them, and they will have the opportunity to retest. 3. In the opinion of the investigator, the subject can and will comply with the requirements of the protocol. 4. Subjects are available to attend all study visits and are reachable by phone throughout the entire study period from day -1 until 24 weeks following last vaccination (end of study). 5. Subject is a male or non-pregnant and non-lactating female age ≥ 18 and ≤ 55 years and in good health at time of ABNCoV2 administration. 6. Subject agrees to their general practitioner (GP) being informed about participation in the study and agrees to sign a form to request the release by their GP, and medical specialist when necessary, of any relevant medical information concerning possible contra-indications for participation in the study to the investigator(s). 7. The subject agrees to refrain from blood donation to Sanquin or for other purposes throughout the study period according to current Sanquin guidelines. 8. Female subjects of non-childbearing potential may be enrolled in the study. Non-childbearing potential is defined as pre-menarche, current bilateral tubal ligation or occlusion, hysterectomy, bilateral ovariectomy or post-menopause. All other female subjects must agree to use continuous adequate contraception2 for the duration of the study. Female subjects must have a negative pregnancy test at the inclusion visit.

Patient Exclusion Criteria

Any clinically significant abnormal finding on clinical examination or laboratory screening tests according to the US Food and Drug Administration (FDA) Toxicity Grading Scale for Healthy Adult and Adolescent Subjects Enrolled in Preventative Vaccine Clinical Trials [30]. 2. History of COVID-19 infection. 3. Chronic use of immunosuppressive drugs or other immune modifying drugs within six months prior to study onset (inhaled and topical corticosteroids and oral anti-histamines exempted) or expected use of such during the study period. 4. Positive urine toxicology test for cannabis, cocaine or amphetamines at inclusion. 5. Screening tests positive for SARS-CoV-2, SARS-CoV-2 antibodies, Human Immunodeficiency Virus (HIV), active Hepatitis B Virus (HBV), or Hepatitis C Virus (HCV). 6. Receipt of any investigational or non-registered product (drug or vaccine) other than the study product in the 30 days preceding enrolment or during the study period. 7. Participation in any other clinical study in the 30 days prior to the start of the study or during the study period. 8. Immunization with any vaccines within the past four weeks or planned receipt of a vaccine during the study period with the exception of a licensed SARS-CoV-2 vaccine, given within the framework of the national SARS-CoV-2 vaccination campaign. The time between last vaccination with ABNCoV2 and a SARS-CoV-2 vaccine provided by the campaign shall be at least 4 weeks. 9. Known hypersensitivity to any of the vaccine components (adjuvant or protein). 10. Administration of immunoglobulins and/or any blood products within the three months prior to the first dose of ABNCoV2 or planned administration during the study period. 11. Previous participation in a COVID-19 vaccine study. 12. Body Mass Index (BMI) >35 kg/m2. 13. Pregnancy, lactation or intention to become pregnant during the study period. 14. History of drug or alcohol abuse interfering with normal functioning in the five years preceding enrolment. 15. Being an employee or student of the department of Medical Microbiology of the Radboudumc, or a person otherwise related to the investigator other than a professional relationship for clinical trial purpose only. 16. Any other condition or situation that would, in the opinion of the investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol.