Unequal Access to Testing and Vaccination Services for the Homeless and Undocumented Population During COVID-19 Pandemic.

To furnish a model to ensure access and use of healthcare services to the undocumented and homeless population. Between March 2020 and October 2021, public and third sector actors in Rome implemented an accessible COVID-19 screening service and vaccination program targeting the homeless and undocumented population. 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% 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. 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.