For cancer patients, Covid-19 presents a particular risk due to their often weakened immune system, weakened by therapy or disease, which is why vaccination is very important for their protection. Now, a recent study by MedUni Vienna shows that, thanks to Omicron, there is an increasing number of breakthrough infections in people with cancer, especially while they are undergoing cancer treatment. The researchers of the study, which has just been published in the journal cancer cellemphasize that compliance with protective measures and the development of vaccines adapted to viral variants are important for those affected.
A total of 3,959 patients who are or have been treated for cancer at the University Hospital of Vienna and at the Franz Tappeiner Hospital in Merano (Italy) were examined in the study. Eighty-five (85)% of patients had received at least one vaccination with one of the SARS-CoV-2 vaccines authorized in the EU. Between February 2020 and February 2022, a total of 950 of 3,959 cancer patients (24%) had been infected with the SARS-CoV-2 virus. As research shows, the number of breakthrough infections increased significantly with the emergence of the Omicron variant in January 2022: 70% of infected patients were vaccinated. Thus, the risk of vaccine breakthrough for cancer patients thanks to Omicron has tripled compared to the Delta variant which prevailed between October and December. Breakthrough infections were significantly more common in those on systemic therapy than in those not on cancer treatment.
To obtain the reasons for the higher rate of breakthrough infections with Omicron compared to Delta, the researchers examined, among other things, the concentration of protective antibodies in the blood of samples from 78 cancer patients and 25 people in good health. Strikingly, in both people with solid tumors and blood cancers, there was significantly reduced inhibition of the Omicron variant by specific vaccine antibodies compared to people without cancer. However, there was also a trend of shorter hospital stays for vaccinated patients compared to unvaccinated patients. In addition, breakthrough infections only required intensive medical care in rare cases.
Protective measures still important for cancer patients
Matthias Preusser, Head of the Division of Oncology in the Department of Medicine I at MedUni Vienna and University Hospital Vienna, says: “The increasing rates of breakthrough infections and hospitalizations of vaccinated cancer patients associated with Omicron underline the need for additional protective measures not only to effectively combat the ongoing pandemic, but also to prepare for the potential emergence of additional variants of Sars-CoV-2. Vaccines tailored to the particular variant of Sars-CoV- 2 could help better protect cancer patients and maintain life-saving cancer treatment throughout the course of the disease. the pandemic.”
As study director, Preusser conducted the study in cooperation with the Haemato-Oncology Day Clinic of the Franz Tappeiner Hospital in Merano (Italy), the Center for Pathophysiology, Infectiology and Immunology of MedUni Vienna, the Clinical Institute for Laboratory Medicine, the Department of Infections and Tropical Medicine (Department of Medicine I) at MedUni Vienna, the Department of Artificial Intelligence and Human Interfaces and the Intelligent Data Analysis Laboratory of Salzburg at the University of Salzburg and the Faculty of Economics at the University of Klagenfurt.