A Study to Assess the Safety, Pharmacokinetics, and Antiviral Activity of ABI-5366 in Healthy Participants and Participants Seropositive for HSV-2 With Recurrent Genital Herpes

Part A: Inclusion Criteria:

• Subject has a body mass index (BMI) between ≥ 18.0 and < 32.0 kg/m2
• In good health (as determined by the Investigator) based on medical history, physical examination, ECG, and clinical laboratory results.
• Female subjects must be non-pregnant and have a negative serum pregnancy test at Screening and a negative urine pregnancy test at Day -1 or Day 1 (predose)
• Agreement to comply with protocol-specified contraceptive requirements

Part B: Inclusion Criteria:

• Subject has a body mass index (BMI) between ≥ 18.0 and < 32.0 kg/m2
• Other than HSV infection, is in good health (as determined by the Investigator) based on medical history, physical examination, ECG, and clinical laboratory results.
• Female subjects must be non-pregnant and have a negative serum pregnancy test at Screening and a negative urine pregnancy test at Day 1 (predose)
• Agreement to comply with protocol-specified contraceptive requirements

Part A and B: Exclusion Criteria:

• Current infection of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), acute hepatitis A virus (HAV), or acute hepatitis E virus (HEV).
• History of any illness that, in the opinion of the Investigator, might confound the results of the study, pose an additional risk in administering study drug to the subject, or a condition known to interfere with the absorption/distribution/elimination of drugs.
• History of any significant drug-related allergic reactions such as anaphylaxis, Stevens-Johnson syndrome, urticaria, or multiple drug allergies
• History of persistent alcohol abuse or illicit drug abuse within 3 years prior to Screening
• Has participated in a clinical study involving administration of either an investigational or a marketed drug within 30 days or 5 half-lives before Screening, whichever is longer.