A Study to Evaluate the Safety, Reactogenicity and Immunogenicity of Vaccine CVnCoV in Healthy Adults for COVID-19

Inclusion Criteria for all participants: * Healthy male and female participants aged 18 to 60 years inclusive. Healthy participant is defined as an individual who is in good general health, not having any mental or physical disorder requiring regular or frequent medication. * Expected to be compliant with protocol procedures and available for clinical follow-up through the last planned visit. * Physical examination and laboratory results without clinically significant findings according to the Investigator's assessment. * Body Mass Index (BMI) ≥18.0 and ≤30.0kg/m\^2 (≥18.0 and ≤32.0kg/m2 for participants with SARS-CoV-2 positive serology). * Females: At the time of enrollment, negative human chorionic gonadotropin (hCG) pregnancy test (serum) for women presumed to be of childbearing potential on the day of enrollment. On Day 1 (pre-vaccination): negative urine pregnancy test (hCG), (only required if the serum pregnancy test was performed more than 3 days before). * Females of childbearing potential must use highly effective methods of birth control from 1 month before the first administration of the trial vaccine until 3 months following the last administration. The following methods of birth control are considered highly effective when used consistently and correctly: * Combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation (oral, intravaginal or transdermal); * Progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable or implantable); * Intrauterine devices (IUDs); * Intrauterine hormone-releasing systems (IUSs); * Bilateral tubal occlusion; * Vasectomized partner; * Sexual abstinence (periodic abstinence \[e.g., calendar, ovulation, symptothermal and post-ovulation methods\] and withdrawal are not acceptable). Exclusion Criteria: The following criterion applies to all open-label sentinel participants: * Participants with SARS-CoV-2 positive serology as confirmed by testing at enrollment. The following criteria apply to all participants, except those with SARS-CoV-2 positive serology: * Participants considered at the Investigator's discretion to be at increased risk to acquire COVID-19 disease (including, but not limited to, health care workers with direct involvement in patient care or care of long-term care recipients). * History of confirmed COVID-19 disease or known exposure to an individual with confirmed COVID-19 disease or SARS-CoV-2 infection within the past 2 weeks. The following criteria apply to all participants: * Use of any investigational or non-registered product (vaccine or drug) other than the trial vaccine within 28 days preceding the administration of the trial vaccine, or planned use during the trial period. * Receipt of any other vaccines within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to enrollment in this trial or planned receipt of any vaccine within 28 days of trial vaccine administration. * Receipt of any investigational SARS-CoV-2 or other CoV vaccine prior to the administration of the trial vaccine. * Any treatment with immunosuppressants or other immune-modifying drugs within 6 months prior to the administration of the trial vaccine or planned use during the trial, with the exception of topically-applied steroids. Corticosteroids used in the context of COVID-19 disease of participants with SARS CoV 2 positive serology are not exclusionary. * Any medically diagnosed or suspected immunosuppressive or immunodeficient condition based on medical history and physical examination, including known human immunodeficiency virus infection, hepatitis B virus infection and hepatitis C virus infection. * History of a pIMD (potential immune-mediated disease). * History of angioedema. * Any known allergy, including allergy to any component of CVnCoV or aminoglycoside antibiotics. A history of hay fever or seasonal allergies (pollinosis) that does not require current treatment (e.g., anti-histamines) during the vaccination period (1 month before first vaccination until 1 month after last vaccination) is not exclusionary. * History of or current alcohol and/or drug abuse. * Participants who are active smokers, were active smokers within the last year (including any vaping in the last year) or have a total smoking history ≥10 pack years. * Active or currently active SARS-CoV-2 infection as confirmed by reactive PCR within 3 days of first trial vaccine administration. * History of confirmed SARS or MERS * Administration of immunoglobulins (Igs) and/or any blood products within the 3 months preceding the administration of any dose of the trial vaccine. * Presence or evidence of significant acute or chronic, medical or psychiatric illness. Significant medical or psychiatric illnesses include but are not limited to: * Respiratory disease (e.g., chronic obstructive pulmonary disease \[COPD\], asthma) requiring daily medications currently or any treatment of respiratory disease exacerbations (e.g., asthma exacerbation) in the last 5 years. * Respiratory disease with clinically significant dyspnea in the last 5 years (except COVID-19 disease in participants with SARS-CoV-2 positive serology). * Asthma medications: inhaled, oral, or intravenous (IV) corticosteroids, leukotriene modifiers, long- and short-acting beta agonists, theophylline, ipratropium, biologics. * Significant cardiovascular disease (e.g., congestive heart failure, cardiomyopathy, ischemic heart disease, history of stroke, peripheral artery disease, pulmonary embolism) or history of myocarditis or pericarditis as an adult. * Elevated blood pressure or hypertension, even if well-controlled. * Diabetes mellitus type 1 or 2. * History of any neurological disorders or seizures including Guillain-Barré syndrome, with the exception of febrile seizures during childhood. * Current or past malignancy, unless completely resolved without sequelae for \>5 years. * Foreseeable non-compliance with protocol as judged by the Investigator. * For females: pregnancy or lactation. * History of any anaphylactic reactions. * Participants with impaired coagulation or any bleeding disorder in whom an IM injection or a blood draw is contraindicated. * Participants employed by the Sponsor, Investigator or trial site, or relatives of research staff working on this trial.