A research team led by Matthias Preusser, MD, PhD, Professor of Medical Oncology and Head of the Clinical Division of Oncology at the Medical University of Vienna, had already demonstrated that patients with cancer may benefit from a third vaccination to protect them against COVID-19. A recent study now also supports a fourth vaccination for this vulnerable group. However, passive immunization by administering an antibody combination to patients with cancer may not provide adequate protection, according to a study published by Mair et al in JAMA Oncology.
Matthias Preusser, MD, PhD
Seventy-two patients with various cancer types participated in the study. Fifty-four of them received a fourth vaccination with one of the currently approved vaccines (active immunization), and 18 underwent passive immunization with the antibody combination tixagevimab/cilgavimab. In order to assess immunity, the investigators compared antibody levels and their inhibitory effect against the SARS–CoV-2 subvariants Omicron BA.1 and BA.4 after three and four vaccinations and following administration of the antibody combination.
Significant Increase in Antibody Levels Following Vaccination
Patients with solid tumors and those with hematologic cancers not on anti–B-cell therapy showed a significant increase in antibody levels after a fourth dose of one of the currently approved vaccines. Based on the obtained data, study leader Dr. Preusser concluded that the administration of a fourth vaccination should be endorsed in patients with cancer, even in the absence of variant-specific vaccines. However, this is not the case for passive immunization of patients.
"Our results suggest that immunization with tixagevimab/cilgavimab does not effectively block the most recently dominant BA.4 variant," said first study author, Maximilian Mair, MD, of the Clinical Division of Oncology at the Medical University of Vienna.
Further studies are required to confirm the results and support the vaccination recommendations. Moreover, there is still a lack of reliable information allowing the definition of a valid threshold for sufficient antibody levels to provide adequate protection against SARS–CoV-2 infection.
Protecting a Vulnerable Patient Group
Patients with cancer are often on immunosuppressive therapies. As a result, patients with cancer are particularly at risk of developing severe clinical courses of COVID-19, underscoring the importance of SARS–CoV-2 vaccination.
"We recommend a prompt fourth vaccination for the particularly vulnerable group of patients with cancer. In addition to this, our patients continue to rely on the protection provided by a responsible society, and control measures such as isolation of infected individuals and the wearing of face masks in indoor settings. Furthermore, even mild cases of COVID-19 can lead to deferral of urgently needed cancer treatments, which can adversely affect the cancer prognosis," underlined Dr. Preusser, as COVID-19 restrictions are increasingly being lifted.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
