A Study To Learn About The Study Vaccine (Called Self-Amplifying Ribonucleic Acid (RNA)) For The Prevention of Influenza

Exclusion Criteria

• •Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• •History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention.
• •Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
• •Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection.
• •Women who are pregnant or breastfeeding.
• •Allergy to egg proteins (egg or egg products) or chicken proteins.
• •Participant who has had significant exposure to laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 infection), coronavirus disease 2019 (COVID-19), or influenza in the past 14 days known prior to Visit 1
• •Any participant who has a SARS-CoV-2 RT-PCR or antigen test in the past 10 days prior to Visit 1 that has not been confirmed as negative.
• •Individuals who receive treatment with radiotherapy or immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids, eg, for cancer or an autoimmune disease, or planned receipt throughout the study.
• •Receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies, from 60 days before study intervention administration, or planned receipt throughout the study.
• •Vaccination with any influenza vaccine within 6 months (175 days) before study intervention administration.
• •Any participant who has received or plans to receive a nucleoside-modified messenger ribonucleic acid (modRNA)-platform SARS-CoV-2 vaccine within 60 days of Visit 1
• •Previous vaccination with an saRNA or an alphavirus replicon vaccine preparation.
• •Participation in other studies involving study intervention within 28 days prior to study entry and/or during study participation.
• •Screening hematology/blood chemistry lab \>=Grade 1 abnormality. Except Bilirubin, other stable Grade1 abnormalities may be considered eligible by Investigator.
• •Screening electrocardiogram (ECG) that is consistent with probable or possible myocarditis or pericarditis, or demonstrates clinically relevant abnormalities that may affect participant safety or study results.
• •Investigator site staff or Pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.
• •Participation in strenuous or endurance exercise through Visit 3.
• •Prior history of heart disease.