A Study to Evaluate the Safety and Immunogenicity of GlaxoSmithKline Biologicals' Influenza Vaccine GSK3206641A Administered in Adults 18 to 64 Years of Age and 65 Years of Age and Older

Inclusion Criteria: * Healthy participants as established by medical history and clinical examination before entering into the study. * A male or female ≥ 18 years of age at the time of first vaccination. * Participants, who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g. completion of the diary cards and COVID-19 assessment card, return for follow-up visits, or return the diary cards and COVID-19 assessment card in a timely manner using the pre stamped envelope received at the site). * Written or witnessed/thumb printed informed consent obtained from the participant prior to performance of any study specific procedure. * 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 hysterectomy, bilateral ovariectomy or post-menopause. * Female participants of childbearing potential may be enrolled in the study, if the participant: * has practiced adequate contraception for 1 month prior to vaccination, and * has a negative pregnancy test on the day of vaccination, and * has agreed to continue adequate contraception during the entire treatment period and for 2 months after completion of the vaccination series. Exclusion Criteria: * Current diagnosis or history of autoimmune disorder(s). * History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccine. * Hyper…