PF-07852352

The purpose of this clinical trial is to learn about the safety and effects of the study vaccine for the potential prevention of influenza. The study vaccine is called Self-Amplifying Ribonucleic Acid vaccine (saRNA vaccine). This study is seeking participants who:
Are between the age of 18 to 49 years old.
Are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures.
Are healthy as determined by medical history, physical examinations, and the study doctor.
For male participants, can father children and willing to use an acceptable method of contraception. Female participants who are not of childbearing potential; or male participant not able to father children.
Are capable of giving signed informed consent. Participants will receive either the saRNA vaccine, a licensed Influenza Vaccine (QIV) or a placebo. Participants will not know which vaccine they receive in advance. A placebo does not have any medicine in it but looks just like the study medicine. Participants will receive the study vaccines as a single shot in the arm. We will compare participant experiences to help us determine if the saRNA vaccine is safe and effective. Participants will take part in this study for 6 months. During this time, they will receive the study vaccine and participate in follow-up visits.