a study of ad26.cov2.s for the prevention of sars-cov-2-mediated covid-19 in adults

Conditions: Participants With or Without Stable Co-morbidities Associated With Progression to Severe COVID-19

Summary: the study will evaluate the efficacy of ad26.cov2.s in the prevention of molecularly confirmed moderate to severe/critical coronavirus disease-2019 (covid-19), as compared to placebo, in sars-cov-2 seronegative adults in the double-blind phase and to describe covid-19 outcomes, safety, and immunogenicity in the different study cohorts in open-label phase.

the aim of the covid-19 vaccine clinical development program is to develop a safe and effective vaccine for the prevention of covid-19. ad26.cov2.s, a covid-19 vaccine based on a human replication-incompetent ad26 vector, constructed to encode the severe acute respiratory syndrome coronavirus-2 (sars-cov-2) virus spike (s) protein, is being developed. the study will consist of: a screening phase (up to 28 days), study period (60-week), and a long-term follow-up period (1 additional year). the total study duration will be maximum 2 years and 3 months for the participants. assessments for efficacy (covid-19 signs and symptoms, etc.), immunogenicity (such as humoral immune responses), and safety (such as adverse events \[aes\] monitoring) will be performed throughout the study.

Eligibility criteria:
inclusion criteria: * contraceptive (birth control) use should be consistent with local regulations regarding the acceptable methods of contraception for those participating in clinical studies * all participants of childbearing potential must: have a negative highly sensitive urine pregnancy test at screening; and have a negative highly sensitive urine pregnancy test immediately prior to each study vaccine administration * participant agrees to not donate bone marrow, blood, and blood products from the first study vaccine administration until 3 months after receiving the last dose of study vaccine * must be willing to provide verifiable identification, has means to be contacted and to contact the investigator during the study * must be able to read, understand, and complete questionnaires in the electronic clinical outcome assessment (ecoa) (that is, the coronavirus disease-2019 \[covid 19\] signs and symptoms surveillance question, the e-diary, and the electronic patient-reported outcomes (epros) exclusion criteria: * participant has a clinically significant acute illness (this does not include minor illnesses such as diarrhea or mild upper respiratory tract infection) or temperature greater than or equal to (\>=) 38.0 degree celsius (100.4-degree fahrenheit) within 24 hours prior to the planned first dose of study vaccine; randomization at a later date is permitted at the discretion of the investigator and after consultation with the sponsor * participant has a known or suspected allergy or history of anaphylaxis or other serious adverse reactions to vaccines or their excipients * participant received or plans to receive: (a) licensed live attenuated vaccines - within 28 days before or after planned administration of study vaccine; and (b) other licensed (not live) vaccines - within 14 days before or after planned administration of study vaccine * participant previously received a coronavirus vaccine * participant received an investigational drug within 30 days (including investigational drugs for prophylaxis of covid-19) or used an invasive investigational medical device within 30 days or received investigational immunoglobulin (ig) or investigational monoclonal antibodies within 3 months, or received convalescent serum for covid-19 treatment within 4 months or received an investigational vaccine (including investigational adenoviral-vectored vaccines) within 6 months before the planned administration of the first dose of study vaccine or is currently enrolled or plans to participate in another investigational study during the course of this study