Safety Study of MucoCept-CVN

Inclusion Criteria: 1. Healthy pre-menopausal women 18-45 years of age, inclusive, with regular predictable menstrual cycles 2. Ability to read and consent in English 3. Previous experience of gynecological examinations 4. Consent to participate and adhere to all procedures, including frequent visits at the UCSF Clinical Research Center (CRC) facility for at least 53 days 5. Agree to get tested for STIs and a Pap Smear 6. Agree not to use any other vaginal product during the course of the study, including spermicides 7. Agree to sexual abstinence (no vaginal, anal, and receptive oral intercourse) until the elimination of L. jensenii 1153-1666 is confirmed and for 12 hours prior to the final study visit after clearance is confirmed 8. For participants with male sexual partners: Agree to use two forms of contraception, condoms plus hormonal or permanent method (intrauterine device \[IUD\] or tubal ligation) during vaginal intercourse from the time clearance is established to the Final Visit 30 days after clearance. Use of spermicides is not permitted. 9. For participants with female sexual partners: Agree to use female condoms during intercourse from the time clearance is established to the Final Visit 30 days after clearance. Use of hormonal or permanent method of contraception (IUD or tubal ligation) is not required. 10. Agree to inform their sexual partner about the goals of the study and importance of sexual abstinence (no vaginal, anal, and receptive oral intercourse) and present with their partner at enrollment visit for separate consent procedure for partners Current sexual partners of participants must meet all the following criteria to be enrolled: 1. Ability to read and consent in English 2. Consent to participate and adhere to all procedures for sexual partners should exposure to L. jensenii 1153-1666 be suspected, including multiple visits at the UCSF Clinical Research Center (CRC) 3. Agree to sexual abstinence (no vaginal, anal, and receptive oral intercourse) until the elimination of L. jensenii 1153-1666 is confirmed, and for 12 hours prior to the final study visit after clearance is confirmed Exclusion Criteria: 1. Urogenital infection, including UTI, Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, HIV-1/2, BV, or vulvovaginal candidiasis 2. Abnormal Pap smear result 3. Pregnancy or within two months of last pregnancy or lactation 4. Antibiotic or antifungal therapy (vaginal or systemic) within 30 days of enrollment 5. Investigational or immune-suppressive drug use within 30 days of enrollment visit or 10 half-lives, or planned during the study 6. Intrauterine device insertion or removal, pelvic surgery, cervical cryotherapy, cervical laser or loop electrosurgical procedure, abortion, labioplasty within three months prior to enrollment 7. Findings during the pelvic exam at the enrollment visit involving significant deep disruption of the epithelium (e.g., Herpes genitalis lesions) 8. Known allergy to any component used in MucoCept-CVN or clindamycin and azithromycin in participant or sexual partner(s), including azithromycin-associated cholestatic jaundice. 9. History of transplant surgery, cancer, HIV, diabetes or condition that could facilitate the growth of microorganisms 10. Recent history of drug or alcohol abuse 11. Unwillingness to abstain from sexual activity during study by participant or sexual partner(s) 12. If in a sexual relationship, inability to present with their sexual partner before enrollment 13. If in a sexual relationship, having multiple concurrent partners or anonymous partners. 14. Any other condition which the study clinician feels would limit the participant's ability to be an appropriate study subject 15. History of regional enteritis (Crohn's disease), ulcerative colitis, or "antibiotic-associated" colitis For sexual partners of study participants, the following exclusion criteria apply: 1. Known allergy to any component used in MucoCept-CVN or clindamycin and azithromycin, including azithromycin-associated cholestatic jaundice. 2. Having multiple concurrent sex partners or anonymous sex partners. 3. HIV-1/2 infection 4. Any other condition which the study clinician feels would limit the ability of sexual partner(s) to complete the study 5. Co-enrollment in clinical trials testing study drugs