4. At screening or within the past 2 months: participant-reported symptoms and/or clinical or laboratory diagnosis of active rectal or reproductive tract infection requiring treatment per current Centers for Disease Control and Prevention (CDC) guidelines or symptomatic urinary tract infection (UTI). Infections requiring treatment include Chlamydia (CT), gonorrhea (GC), syphilis, active Herpes Simplex Virus (HSV) lesions, chancroid, genital sores or ulcers, and, if clinically indicated, genital warts. Note that HSV seropositivity with no active genital lesions is not an exclusion criterion, since treatment is not required.