A Study to Evaluate the Safety and Efficacy of CD388 for Prevention of Influenza

Inclusion criteria

• ✓. Must be 12 years of age or older at the time of signing the informed consent.
• ✓. Written informed consent and any locally required authorization (e.g., Health Insurance Portability and Accountability Act \[HIPAA\] in the US) obtained from the participant before performing any protocol-related procedures, including screening evaluations. For participants under the legal age of consent as defined by local regulations, the parent(s) or legal guardian(s) may be required to give their signed written informed consent and participants may sign an assent form as specified by local law.
• ✓. Has negative rapid antigen tests for influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) prior to dosing at Day 1.
• ✓. Weight is ≥ 40 kilograms (kg) at screening.
• ✓. Body Mass Index (BMI; calculated as weight in kg divided by height in meters \[m\] squared)) is ≥ 18 kg/m\^2 at screening.
• ✓. In the opinion of the Investigator, must be able to comply with the requirements of the protocol and be able to read, understand, and complete questionnaires in the electronic diary (eDiary), work with smartphones/tablets/computers (if applicable, with assistance by a caregiver, surrogate, or legally authorized representative), and be willing and able to adhere to the prohibitions and restrictions specified in this protocol. If an appropriate language version is not available for the eDiary assessments, the participant should not be enrolled.
• ✓. Must be assessed by the Investigator as medically stable and not requiring significant change in maintenance therapy and has not been hospitalized for worsening disease or any significant medical event during the 2 months before screening
• ✓. Must agree to the following contraception requirements:

Exclusion criteria