Study to Assess the Immune Response and the Safety Profile of a High-Dose Quadrivalent Influenza Vaccine (QIV-HD) Compared to a Standard-Dose Quadrivalent Influenza Vaccine (QIV-SD) in Taiwanese Adults 65 Years of Age and Older

Primary Objective:

Immunogenicity: To describe the immune response induced by high-dose quadrivalent influenza vaccine (QIV-HD) and AdimFlu-S (QIS) by hemagglutinin inhibition (HAI) measurement method in all participants.

Safety: To describe the safety profile of all participants in each study groups.

The duration of each participant's participation was approximately 28 days (Day 0 through Day 28 \[+ 7 days\]).

Eligibility Criteria:
Inclusion criteria :

* 65 years and older on the day of inclusion.
* Able to attend all scheduled visits and complied with all study procedures.

Exclusion criteria:

* Participation at the time of study enrollment (or in the 4 weeks preceding the study vaccination) or planned participation during the study period in another clinical study investigating a vaccine, drug, medical device, or medical procedure.
* Receipt of any vaccine in the 4 weeks (28 days) preceding the study vaccination or planned receipt of any vaccine prior to Visit 2.
* Previous vaccination against influenza (in the preceding 6 months) with either the study vaccine or another vaccine.
* Receipt of immune globulins, blood or blood-derived products in the past 3 months.
* Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).
* Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine(s) used in the study or to a vaccine containing any of the same substances.
* Thrombocytopenia, bleeding disorder, or receipt of anticoagulants that based on Investigator's judgment contraindicate intramuscular vaccination.
* Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily.
* Alcohol, prescription drug, or substance abuse that, in the opinion of the Investigator, might interfere with the study conduct or completion.
* Chronic illness that, in the opinion of the investigator, was at a stage where it might interfere with trial conduct or completion.
* Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature greater than or equal to \[\>=\] 38.0 degree Celsius). A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
* Personal or family history of Guillain-Barré syndrome.
* Neoplastic disease or any hematologic malignancy (except localized skin or prostate cancer that was stable at the time of vaccination in the absence of therapy and participants who had a history of neoplastic disease and had been disease free for \>=5 years).
* Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (i.e., parent, spouse) of the Investigator or employee with direct involvement in the proposed study.

The above information was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.