A Study on the Immune Response and Safety of the Shingles Vaccine and the Influenza Vaccine When Either is Given to Healthy Adults at the Same Time or Following a COVID-19 Booster Vaccine

Inclusion Criteria

• Participants who in the opinion of the investigator, can and who will comply with the requirements of the protocol (e.g., completion of the eDiaries, return for follow-up visits).
• Written informed consent obtained from the participant prior to performance of any study-specific procedure.
• Age at study entry:
• For HZ/su and mRNA-1273 booster cohort: A male or female aged 50 years or older at the time of randomization.
• For Flu D-QIV and mRNA-1273 booster cohort: A male or female aged 18 years or older at the time of enrollment.
• Healthy participants or medically stable patients as established by medical history and clinical examination at screening. A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 3 months before enrolment.
• Participants who have a documented previous mRNA-1273 primary vaccination series completed (i.e., both doses) at least 6 months prior to first vaccination.
• Female participants of non-childbearing potential may be enrolled in the study. Non-childbearing potential is defined as pre-menarche, current bilateral tubal ligation or occlusion, documented total hysterectomy, bilateral ovariectomy, or bilateral salpingectomy, or post-menopause.
• Female participants of childbearing potential may be enrolled in the study, if the participant:
• Has practiced effective contraception for 1 month prior to study intervention administration, and
• Has a negative pregnancy test on the day of study intervention administration, and
• Has agreed to continue effective contraception during the study until 2 months after completion of the study vaccination series.

Exclusion Criteria

Medical conditions

• Any clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study or might confound post-study intervention administration safety assessments (e.g., tattoos overlying either study intervention administration site).
• History of any reaction or hypersensitivity likely to be exacerbated by any component of the study interventions, including a known history of severe allergic reaction (e.g., anaphylaxis) to any component of any of the study vaccines.
• Any history of Guillain-Barré syndrome.
• Any history of myocarditis or pericarditis.
• Acute or chronic clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by medical history or physical examination.
• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
• Hypersensitivity to latex.
• For HZ/su and mRNA-1273 booster cohort: history of Herpes Zoster.

Prior/concomitant therapy

• Use of any investigational or non-registered product (drug, vaccine or medical device) other than the study intervention(s) during the period beginning 30 days before the first dose of study intervention(s) (Day -29 to Day 1), or their planned use during the study period.
• Planned administration/administration of a vaccine not foreseen by the study protocol in the period starting 30 days before first dose and ending 30 days after the last dose of study intervention administration. However, for HZ/su and mRNA-1273 booster cohort: licensed pneumococcal vaccines and non-replicating vaccines (i.e., inactivated and subunit vaccines, including inactivated and subunit influenza vaccines, with or without adjuvant for seasonal or pandemic flu) may be administered up until 8 days prior to dose 1 of HZ/su and/or dose 2 of HZ/su and/or at least 14 days after any dose of HZ/su. For Flu D-QIV and mRNA-1273 booster cohort: licensed pneumococcal vaccines and non-replicating vaccines (i.e., inactivated and subunit vaccines, other than influenza vaccines) may be administered up until 8 days prior to dose 1 of Flu D-QIV and/or at least 30 days after any dose of Fl