A Study of an Ad26.RSV.preF-based Vaccine and High-dose Seasonal Influenza Vaccine, With and Without Coadministration, in Adults Aged 65 Years and Older

Inclusion Criteria

• Willing and able to adhere to the prohibitions and restrictions specified in this protocol
• In the investigator's clinical judgment, the participant must be in stable health at the time of vaccination. Participants will be included on the basis of medical history and vital signs performed between informed consent from (ICF) signature and vaccination
• Before randomization, a participant must be not intending to conceive by any methods, postmenopausal or surgically sterile
• From the time of vaccination through 3 months after vaccination, agrees not to donate blood
• Must be willing to provide verifiable identification, have means to be contacted and to contact the investigator during the study
• Participant must be able to work with smartphones/tablets/computers

Exclusion Criteria

• History of malignancy within 5 years before screening not in the following categories: a) participants with squamous and basal cell carcinomas of the skin and carcinoma in situ of the cervix may be enrolled at the discretion of the investigator; b) participants with a history of malignancy within 5 years before screening, with minimal risk of recurrence per investigator's judgement, can be enrolled
• Known or suspected allergy or history of anaphylaxis or other serious adverse reactions to vaccines or their excipients (including specifically the excipients of the study vaccine)
• History of severe allergic reactions (example, anaphylaxis) to any component of the Quadrivalent high-dose influenza vaccine, including egg protein, or following a previous dose of any influenza vaccine
• Has abnormal function of the immune system resulting from either clinical condition, chronic or recurrent use of systemic corticosteroids within 2 months prior to study vaccination, or immunomodulating agents within 6 months prior to study vaccination
• Per medical history, participant has chronic active hepatitis B or hepatitis C infection
• History of acute polyneuropathy (example, Guillain-Barre syndrome) or chronic idiopathic demyelinating polyneuropathy
• Has a serious chronic disorder, example, chronic obstructive pulmonary disease or congestive heart failure, end-stage renal disease with or without dialysis, clinically unstable cardiac disease, Alzheimer's disease, or has any condition, including conditions placing the participant at high risk for severe influenza, for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments
• Received vaccination with seasonal influenza vaccine for the current influenza season in the Northern Hemisphere