HMN 2025: what is the new Guideline on respiratory infections in leukemia

People with leukemia have a weakened immune system due to the disease itself and treatment, which leads to an increased susceptibility to infections. In a revised guideline, experts summarize the findings of the past ten years on all viruses that cause respiratory infections: How dangerous are they in detail? How are they diagnosed? Are hygiene measures necessary? What treatment and vaccination strategies are available?

Professor Marie von Lilienfeld-Toal from the Institute for Diversity Medicine at Ruhr University Bochum, Germany, is the lead author of the recommendations of the European Conference on Infections in Leukemia (ECIL) on the diagnosis, prevention, and treatment of community-acquired respiratory viral infections (CARV), which was published on August 27, 2025 in the journal The Lancet Infectious Diseases.

Infections are more dangerous

“Patients with cancer of the blood are particularly susceptible to respiratory infections, especially in the early stages of the disease or during and after highly immunosuppressive therapies, such as stem cell transplantation,” says von Lilienfeld-Toal. “Many infections that otherwise healthy people consider trivial are more dangerous in this group. Influenza infection, for example, is fatal in 10% of cases, and people also shed the virus for longer.”

The increased risk was also clearly evident with SARS-CoV-2, and patients were also less well protected by vaccinations. Depending on the treatment, those affected are particularly susceptible to infections for about a year.

To revise the guideline, the team analyzed current specialist literature from 2014 to 2024. Publications on adenovirus, bocavirus, coronavirus, influenza virus, metapneumovirus, parainfluenza virus, respiratory syncytial virus, and rhinovirus in patients with hematologic malignancies (blood cancer, HM) and/or hematopoietic cell transplantation were included.

“In the current recommendations, we outline a common approach for controlling such infections, for laboratory diagnostics including SARS-CoV-2, as well as specific infection control strategies for respiratory tract infections other than SARS-CoV-2,” summarizes von Lilienfeld-Toal.

Vaccines and special recommendations for young children

Seasonal inactivated vaccines and early antiviral therapy are recommended for influenza virus prevention, while experts do not advocate for general antiviral prophylaxis. For respiratory syncytial virus (RSV), approved vaccines may be considered depending on local approval, although the evidence for patients with leukemia is limited.

Passive immunization with Palivizumab or Nirsevimab is recommended for children under two years of age, but there are insufficient data on pre- or post-exposure prophylaxis or treatment for older children or adult patients. For patients with severe immunodeficiency following a stem cell transplant, the guidelines recommend the administration of ribavirin and/or intravenous immunoglobulins.

For other respiratory infections, only supportive measures are available to improve immune function and correct antibody deficiencies. This includes reducing the administration of medications containing cortisone as much as possible.

“Evidence gaps exist primarily in the areas of immunization and antiviral therapies,” says von Lilienfeld-Toal.

Recommendations for treating physicians, relatives, and patients

These recommendations are relevant for everyone treating persons with leukemia. Since viral respiratory infections often originate from the environment, this is relevant not only in specialized clinics, but also in outpatient clinics and primary care practices. Family caregivers can also benefit from this information, as can people with leukemia themselves, who usually receive such information in a processed form from their treating physicians.