Vaccination against influenza reduces the severity of the infection in patients with an allogeneic hematopoietic stem cell transplant, as demonstrated by research led by the INCLIVA Health Research Institute and the University Clinical Hospital of Valencia. The work concludes that immunization acts as a protective factor against the most serious forms of the disease in people with blood cancer subjected to a situation of high immunosuppression.
The results show that vaccinated patients have a lower risk of progression to lower respiratory disease, such as pneumonia, as well as a lower probability of hospitalization and needing oxygen. The study thus provides relevant clinical evidence in a group that is especially vulnerable to respiratory viruses.
Allogeneic hematopoietic stem cell transplantation consists of transferring blood stem cells from a donor to a recipient to replace their hematopoietic system. This procedure is used in diseases such as leukemias, lymphomas or myelodysplasias, and involves high immunosuppression, which increases the risk of infections such as the flu.
Respiratory viruses and hematological patients
The doctor José Luis Piñanafrom the Hematology Unit of the Clinical Hospital and the Hematopoietic Transplant Research Group, explained that a respiratory virus can mean for these patients “a prolonged hospital admission, severe pneumonia, the need for oxygen or even an admission to the intensive care unit.”
In this area, the teams of the Hematology Unit, directed by Carlos Solanoand the Microbiology Unit, directed by David Navarrohave consolidated a joint line of work that has placed Valencia as an international benchmark in research on respiratory viruses in patients with hematological cancer.
Validation of a tool to measure risk
In addition to confirming the protective effect of the vaccine, the research has made it possible to validate a risk scoring system that helps classify these patients according to their vulnerability to influenza. This tool could facilitate more intensive prevention and treatment strategies in cases with a higher risk of complications.
The new work expands previous results from this same research group. Specifically, it analyzes 143 adult patients who had received an allogeneic transplant between 2012 y 2023with a total of 214 flu episodes. As Piñana explains, “many people ask themselves: if I got vaccinated and still had the flu, has it served any purpose?” Our study shows that yes.
Consolidated line of research
The professionals involved have been 15 years investigating the impact of respiratory viruses in allogeneic transplant recipients, with a clinical-microbiological registry that has allowed us to delve deeper into the epidemiology, prevention and evolution of these infections.
This journey has also resulted in participation in recommendations and international reference guides on infections in hematological patients. These include European and American documents focused on the prevention, diagnosis and treatment of respiratory infections in hematopoietic transplant recipients and cellular therapies.
With this new evidence, researchers reinforce the role of influenza vaccination not only in preventing infections, but also in reducing its clinical impact when the disease occurs.
