AUTHOR=Morrone Aldo , Buonomini Anna Rita , Sannella Alessandra , Pimpinelli Fulvia , Rotulo Arianna TITLE=Unequal Access to Testing and Vaccination Services for the Homeless and Undocumented Population During COVID-19 Pandemic JOURNAL=International Journal of Public Health VOLUME=Volume 67 - 2022 YEAR=2022 URL=https://www.ssph-journal.org/journals/international-journal-of-public-health/articles/10.3389/ijph.2022.1604851 DOI=10.3389/ijph.2022.1604851 ISSN=1661-8564 ABSTRACT=Introduction Barriers to access to healthcare for the homeless and undocumented patients have increased during the pandemic. This study furnishes a model to ensure adequate access and use of services to the undocumented and homeless population in Rome. Methods Contingent to ethical approval, public and third sector actors in Rome implemented an accessible COVID-19 screening service and vaccination program targeting the homeless and undocumented population between March 2020 and October 2021. Results 95,6% of the patients tested negative to both rapid and molecular tests. 0.9% tested positive to both. 0.7% were false negatives, while 2,8% (60) were false positives. None of the participants refused the diagnostic treatment. From July to October 2021, 1384 people received a complete cycle of the COVID-19 vaccine through the program. 632 (45,6%) also agreed to perform the antibodies testing before inoculation. 318 (50.31%) of these were positive at the time of vaccination. Discussion and Conclusion We present a cost-effective model for reducing structural barriers to access diagnostic and preventive services for the homeless and undocumented population that can be applied to different public health settings.