The first study to evaluate the clinical characteristics and outcomes of fully vaccinated patients with cancer who had breakthrough COVID-19 infections indicates they remained at high risk for hospitalization and death. The study, published Dec. 24 in Annals of Oncology, showed that fully vaccinated patients who experienced breakthrough infections had a hospitalization rate of 65%, an ICU or mechanical ventilation rate of 19%, and a 13% death rate. The study was conducted by the COVID-19 and Cancer Consortium (CCC19), a group of 129 research centres that has been tracking the impact of COVID-19 on patients with cancer since the beginning of the pandemic. Patients were considered fully vaccinated after having received two doses of either the BioNTech, Pfizer vaccine or the Moderna, NIAD vaccine, or one dose of the J&J vaccine, with the last vaccine dose long enough before breakthrough COVID-19, to consider them as fully vaccinated. The data was collected between Nov. 1, 2020, and May 31, 2021, before booster vaccines were recommended for patients with cancer by the U.S. Centers for Disease Control and Prevention. The consortium identified 1,787 patients with cancer and COVID-19 for the study, the vast majority of which were unvaccinated. The number of fully vaccinated was 54, and 46% of those fully vaccinated had reduced levels of lymphocytes – the T cells and B cells responsible for immunological responses to viruses. Lymphopenia commonly occurs in patients with cancer receiving anti-CD20 monoclonal antibodies or CAR-T-cell treatments for hematologic malignancies, including lymphoma and leukemia. The study appears to support previous observations that patients with hematologic malignancies are at greater risk for severe outcomes from COVID-19. However, the number of patients in the study is too small to make definitive conclusions about specific types of anticancer therapies that might be associated with breakthrough infections, the researchers noted. Patients on a treatment regimen of corticosteroids also appeared to be more susceptible to hospitalization. “Similar results (high mortality rates among fully vaccinated individuals) have been reported in other immunocompromised patient populations, such as organ transplant recipients, prior to the utilization of additional vaccine doses,” said Dimitrios Farmakiotis, MD, an infectious disease clinician at the Warren Alpert Medical School of Brown University and a senior author of the study. “These findings come at a time of concerns that immune escape mutants such as the omicron strain may emerge from chronically infected patients with weakened immune systems. Thus, the immunosuppressed and their close contacts should be target groups for therapeutic and preventive interventions, including community-level outreach and educational efforts.”
https://medicalxpress.com/news/2021-12-fully-vaccinated-patients-cancer-breakthrough.html
