A Study on the Safety, Reactogenicity and Immune Response of a Vaccine Against Influenza in Healthy Younger and Older Adults

Inclusion Criteria: * A male or female between and including 18 and 45 years of age (YAs) or between and including 60 and 80 years of age (OAs) at the time of the study intervention administration. The age of sentinel participants in OA category will be limited to maximum 70 years. * Healthy or medically stable participants as established by medical history, safety laboratory assessments and clinical examination. * Body mass index \>= 18 kg/m\^2 and \<= 32 kg/m\^2. * Participants who, in the opinion of the investigator, can and will comply with the requirements of the protocol. * Written informed consent obtained from the participant prior to performing any study-specific procedure. * Female participants of non-childbearing potential may be enrolled in the study. * Female participants of childbearing potential may be enrolled in the study if the participant: * has practiced adequate contraception for 28 days prior to study intervention administration, and * has a negative pregnancy test on the day of study intervention administration, and * has agreed to continue adequate contraception for at least 1 month after study intervention administration. Exclusion Criteria: Medical conditions * Acute or chronic clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or review of the participant's medical record. * Any clinically significant hematological coagulation or urine analysis laboratory abnorm…