{
  "abstract": "Background STI clinics are facing a constant increase in new infections since the COVID-19 pandemic. Jenner 44 is a free, open-access STI clinic located in Northern Milan, serving the general population as well as hard-to-reach groups such as homeless individuals, migrants, and undocumented foreigners. Beyond disease detection, reporting, counselling, and treatment, since July 2024 we have implemented a proactive vaccination service for vaccine-preventable STIs - HBV, HAV, HPV and since September 2025, mpox.Materials and Methods We extracted clinical data from our local web-based eCRF, MTSWeb, and matched them with the regional vaccination programme database, ARVAX. Vaccination assessment and administration were primarily conducted by healthcare assistants in collaboration with nurses, with physician supervision and intervention reserved for complex cases. The analysis covered the period from the activation of the Jenner 44 Vaccination Center on the ARVAX platform (April 1, 2025) through December 31, 2025.Results All 2,540 individuals presenting for STI screening underwent systematic assessment of vaccination eligibility based on age, risk exposure, and prior immunization history. Of these, 926 (36.5%) initiated a vaccination course. The vaccinated population comprised 159 females (17.2%) and 767 males (82.8%), with a median age of 33.5 years. Foreign-born individuals represented 23.3% (n=216) of vaccinees, originating from 54 countries across South America (49%: Peru 37%, Brazil 26%), Asia (20%), Africa (11%), Europe (18%, including 58% from Eastern Europe), and Oceania (0.5%). Regarding documentation status within this foreign-born group, 182 (84.3%) had regular national health documentation, 22 (10.2%) held STP codes (Straniero Temporaneamente Presente - temporarily present foreigner), and 12 (5.5%) lacked any eligibility for the National Health System. HPV vaccine was most frequently administered (1,068 doses to 683 individuals), followed by HAV (409 doses to 291 individuals), HBV (262 doses to 163 individuals), and mpox (136 doses to 87 individuals). Regional guidelines initially limited mpox vaccination to contacts of confirmed cases until August 2025, with eligibility expanded thereafter. HBV vaccine was additionally used as a booster to elicit anamnestic responses in 18 individuals applying for HIV post-exposure prophylaxis. The service successfully completed 18 previously incomplete vaccination cycles initiated at other facilities.Conclusion Our experience demonstrates that on-site vaccination services with proactive promotion strategies substantially improve immunization uptake across the general population while proving particularly effective in reaching vulnerable groups - including undocumented migrants and homeless individuals - who face significant barriers to accessing mainstream vaccination services. This model offers a replicable strategy for enhancing vaccine-preventable STI prevention in urban settings.",
  "authors": [
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "F Gullone"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "L Cordier"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "M Morosi"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "E Beyene Teklu"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "C Archetti"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "A Bramati"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "V Ciarutti"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "A Mantineo"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "C Sturniolo"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "E Villa"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "F Pulejo"
    },
    {
      "affiliations": [
        "SSD Fragilità e Prevenzione – STI Clinic Jenner 44 – Department of Infectious Diseases - ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "A Capetti"
    }
  ],
  "title": "SC17 Vaccination coverage and adherence to vaccines in a territorial sexually transmitted infection (STI) clinic in Milan, Italy: the impact of an integrated on-site service",
  "uid": "8eaad66a-784b-5ba0-a28a-8af1e6977e5c"
}