Clinical Post-SARS-CoV-2 Infection Scenarios in Vaccinated and Non-Vaccinated Cancer Patients in Three German Cancer Centers: A Retrospective Analysis

SIMPLE SUMMARY: This study investigated SARS-CoV-2 infections and their impact on cancer in COVID-19 vaccinated (n = 49) and non-vaccinated (n = 84) cancer patients. A mild course of COVID-19 was documented more frequently in vaccinated cancer patients (49% vs. 29%), while the incidence of severe and critical courses occurred in approximately one-half of the non-vaccinated patients (22% vs. 42%). In comparison to non-vaccinated patients, admissions to intermediate and intensive care units and the need for non-invasive and invasive respiratory support were reduced by 71% and 50% among vaccinated patients. The median length of hospital stay was 11 days for non-vaccinated and 5 days for vaccinated patients. COVID-19 mortality was reduced by 83% in vaccinated patients. Finally, the median time from SARS-CoV-2 infection to restarting cancer therapy was 12 and 26 days among vaccinated and non-vaccinated groups, respectively. Our results provide evidence for the significant benefits of COVID-19 vaccines for cancer patients. ABSTRACT: COVID-19 vaccines have become an integral element in the protection of cancer patients against SARS-CoV-2. To date, there are no direct comparisons of the course of COVID-19 infection in cancer patients between the pre- and post-vaccine era. We analyzed SARS-CoV-2 infections and their impact on cancer in COVID-19 vaccinated and non-vaccinated patients from three German cancer centers. Overall, 133 patients with SARS-CoV-2 were enrolled in pre- and post-vaccine eras: 84 non-vaccinated and 49 vaccinated, respectively. A mild course of COVID-19 was documented more frequently in vaccinated patients (49% vs. 29%), while the frequency of severe and critical courses occurred in approximately one-half of the non-vaccinated patients (22% vs. 42%, p = 0.023). Particularly, patients with hematologic neoplasms benefited from vaccination in this context (p = 0.031). Admissions to intermediate- and intensive-care units and the necessity of non-invasive and invasive respiratory support were reduced by 71% and 50% among vaccinated patients, respectively. The median length of admission was 11 days for non-vaccinated and 5 days for vaccinated patients (p = 0.002). COVID-19 mortality was reduced by 83% in vaccinated patients (p = 0.046). Finally, the median time from SARS-CoV-2 infection to restarting cancer therapy was 12 and 26 days among vaccinated and non-vaccinated groups, respectively (p = 0.002). Although this study does not have enough power to perform multivariate analyses to account for confounders, it provides data on COVID-19 in non-vaccinated and vaccinated cancer patients and illustrates the potential benefits of COVID-19 vaccines for these patients.