A Study to Learn About Flu and COVID-19 Vaccine Responses in Healthy People

This study is to learn about flu and COVID vaccines, either alone or when mixed together. Healthy people aged 18 or older can join. Participants will get one shot in each arm, either a flu or COVID vaccine, alone or mixed. The study lasts about 6 months, and participants need to visit the research site at least 3 times.

Inclusion Criteria: * Participants 18 years of age or older * Healthy participants who are determined by medical history, physical examination (if clinically required), and clinical judgment of the investigator to be eligible for inclusion in the study. Exclusion Criteria: * Vaccination with any investigational or licensed 2024-2025 season formulation influenza or COVID-19 vaccine. * Treated with antiviral therapies for influenza (eg, Tamiflu) within 180 days prior to Day 1 Please refer to the study contact for further eligibility details.