Inclusion Criteria:  Donor:  a woman between 18 and 40 years old; generally healthy and do not suffer from an immunological or other chronic diseases; have regular menstruation or do not menstruate due to birth control pills, gestagen pills (mini-pills), etonogestrel birth control implant or hormone IUD; not or do not have a desire to become pregnant within the next year; willing to be asked personal questions in the form of medical history, current use of medication, sexuality and sexual behavior; willing to refrain from vaginal intercourse unless a condom is used during certain periods of participation; and can read and understand information material in Danish or English. Accept not to use any intravaginal products such as tampons, menstrual cup, sex toys, vaginal cleaning products, spermicide products and vaginal lubrication.  Recipient:  a woman between 18 and 40 years old; generally healthy and do not suffer from an immunological or other chronic diseases; have regular menstruation or do not menstruate due to birth control pills, gestagen pills (mini-pills), etonogestrel birth control implant or hormone IUD; not or do not have a desire to become pregnant within the next year; willing to be asked personal questions in the form of medical history, current use of medication, sexuality and sexual behavior; willing to refrain from vaginal intercourse unless a condom is used during certain periods of participation; and can read and understand information material in Danish or English. Accept not to use any intravaginal products such as tampons, menstrual cup, sex toys, vaginal cleaning products, spermicide products and vaginal lubrication.  Exclusion Criteria:  Donor:  Being pregnant Any medical history of bacterial vaginosis, Trichomoniasis, Syphilis, HPV, herpes, intraabdominal infections, recurrent urine infections or Mycoplasma infections. Positive test result of HIV, Hepatitis A, B and C, Chlamydia, Gonorré, Mycoplasma, Trichonomas, HPV, herpes simplex and Streptococcus A, B, C and G. Currently pregnant or lactating. Any history of Gonorré and/or Chlamydia during the last year. Have been travelling or have had a sexual partner who has been travelling to countries with Ebola and/or Zika virus within the last year. Any other medical history, current use of medicine, travels or behavior which from a doctor's perspective is considered not suitable for being a donor. Hysterectomized Have participated in other medical studies within the last 30 days Removal of IUD, cervical cryotheraphy or cervical laser-treatment up until 3 months before screening. Any condition requiring the use of antibiotics in the investigation period Usage of long-acting hormonal therapy within the last 3 months prior to screening. Any social, medical or psychological condition including any history of drug and alcohol abuse, where it is evaluated that the participant cannot adhere to the protocol Unsatisfying examination and screening results evaluated by a doctor Any sexual habits, history or sexual partner, where the behavior can lead to an increased risk of sexual infections. Usage of medicine, recently vaccinated or other behavior which is considered to be a hinder for participation.  Recipient:  Being pregnant Planning to become pregnant within the next 6 months Lactating Being less than 8 weeks post partum Known positive HIV/AIDS infection or other immune diseases Positive test result of HIV, Hepatitis A, B and C, Chlamydia, Gonorré, Mycoplasma, Trichonomas, positive urine hCG and HPV. Have participated in other medical studies within the last 30 days Removal of IUD, cervical cryotheraphy or cervical laser-treatment up until 3 months before screening. Any condition requiring the use of antibiotics in the investigation period Usage of long-acting hormonal therapy within the last 3 months prior to screening. Any social, medical or psychological condition including any history of drug and alcohol abuse, where it is evaluated that the participant cannot adhere to the protocol Unsatisfying examination and screening results evaluated by a doctor