Spreading of SARS-CoV-2 among adult asylum seekers in refugee community shelters in Lübeck, Germany between 2020 and 2022: a mixed-cohort observational and repeated cross-sectional study.

Introduction: Housing and access to healthcare pose particular challenges to asylum seekers and refugees. The main study aim was to assess their frequency of SARS-CoV-2 infection during the COVID-19 pandemic.

Methods: We provide a prospective study on SARS-CoV-2 cases among adult asylum seekers/refugees in Europe over 18 months. Acute SARS-CoV-2 infection and antibody titers were determined in adult refugees living in shared accommodation in Lübeck, Germany, in fall 2020 (TP1) and spring 2021 (TP2) and compared to the results from a local population-based cohort. In spring 2022 (TP3), we determined antibody titers two years into the pandemic and one year of access to vaccination. At TP3, we additionally included a third cohort of recently arrived refugees from Ukraine.

Results: At all three time points, we detected a marked increase in the infection frequency in refugee community shelters compared to the control group. Age, sex, or facility equipment did not impact the results. Refugees living with their own children in the shelter were significantly more often infected than those without. None of the PCR-positive refugees at TP1 and TP2 were aware of their infection. One year later, awareness of having had an infection was still much lower among the refugees compared to the control cohort. Only 32.9% of the asylum seekers were willing to be vaccinated compared to 85.5% in the control population at the beginning of the vaccination period. However, over 90% of the same population was vaccinated one year later. Among newly arrived refugees from Ukraine, uncertainty towards vaccination was significantly increased compared to the control cohort and the group of residing refugees.

Conclusion: Refugees residing in shared accommodations represent a vulnerable group for SARS-CoV-2 infection and transmission. This increased vulnerability does not diminish over time. Initial doubts regarding vaccination are higher among refugees. While this reservation can be overcome, awareness work is paramount and has to start anew with any new refugee wave.