Unequal access to testing and vaccination services for the homeless and undocumented population during the COVID-19 pandemic

Social and health inequities have been a central issue to the current pandemic emergency. The homeless and undocumented population are among the hardest hit segments of society: added to social and material deprivation and ill-health, they face a series of barriers to access healthcare services, making them even more exposed to public health threats. This study provides an epidemiological snapshot of the homeless and undocumented population of Rome, Italy and proposes a sustainable model for healthcare systems to improve access to care for the undocumented and homeless population. In March 2020 the San Gallicano Institute of Rome jointly with the Regional authority and third sector parties carried out a COVID-19 screening service targeting homeless and undocumented people. Patients could access on a walk-in basis or by booking a slot online. The screening consisted in an antigenic diagnostic test (ADT) and a molecular swab (PCR). Results were given 20 minutes later (ADTs) and 24-48 hours (PCR). Isolation in COVID Hotels was arranged for patients positive to ADT upon receipt of PCR. Patients with a positive PCR continued isolation until a negative test. In July 2021 the same institutions carried out a COVID-19 vaccination program. Upon booking a slot, patients were not asked for IDs or proof of residence. Recipients were either given a single dose vaccine (Janssen Ad26.COV2.S COVID-19) or a two-doses Pfizer-BioNTech COVID-19 BNT162b2 mRNA vaccine, according to medical history and risk of discontinuity. Contingent to their consent, blood samples were obtained to test for IgG antibodies targeting the S1 and S2 domains of SARS-CoV-2 spike protein. Between March 2020 and October 2021, 6468 tests were performed for the detection of SARS-CoV2. 95,6% (2082) of patients screened with both tests were negative (i.e., negative ADT and negative PCR test). 0.9% (20) tested positive to both ADT and PCR tests. 0.7% (16) were false negatives, i.e., had a negative ADT dismissed by a positive PCR test, while 2,8% (60) were false positives. None of the participants refused the diagnostic treatment. From July to October 2021, 1384 homeless and undocumented people received a complete cycle of the COVID-19 vaccine through the program. 632 (45,6%) of these also agreed to perform the serum assay of anti-spike antibodies before inoculation. 318 (50.31%) of these were positive at the time of vaccination. In Italy, people affected by COVID-19 have clear stay-at-home orders. This, however, requires that everyone has a home. Shelter access is also contingent to proof of a negative test. However, users cannot access free public tests due to structural and bureaucratic barriers. Similarly, access to vaccines depends on proof of residence, creating a barrier to access to many for different reasons. This study presents a model for testing and vaccinating people facing structural barriers to access healthcare in Rome. The proposed model shows that ensuring access to diagnostic and preventive services to patients without documents can be achieved cost-effectively.