Researchers investigate the protection against meningococcal infection in hematopoietic stem cell transplant recipients

The team in the Hematology Department at Henri Mondor AP-HP Hospital, coordinated by Dr. Christine Robin, and scientists from the Institut Pasteur (the Invasive Bacterial Infections Unit led by Professor Muhamed-Kheir Taha) recently studied protection against meningococcal infection in patients who had received hematopoietic stem cell transplantation. The results of this trial (NCT03509051), sponsored by the Paris Public Hospital Network (AP-HP), were published in Clinical Microbiology and Infection on July 4, 2022.

Meningococcal infection is responsible for severe, often fatal diseases such as meningitis. Patients who have undergone hematopoietic stem cell transplantation (HSCT), for example to treat leukemia, are 30 times more likely than the general population to develop these severe infections.

The most recent meningococcal B vaccine (4CMenB, Bexsero^®) was recommended in France in 2021 for infants under the age of 2 and people at high risk, including HSCT recipients.

In this trial, the research team set out to determine the immunogenic potential of the vaccine in HSCT recipients.

Forty patients between the ages of 31 and 68, who received HSCT between 6 months and 13 years prior to the trial, were included. They were vaccinated with 4CMenB (2 doses 2 months apart).

One month after the second dose, 90% of patients showed antibody levels correlated with protection; nine months later the proportion had fallen to 62%. No severe adverse events were observed.

The trial supports the inclusion of vaccination against meningococcal group B, alongside vaccination against groups A, C, W and Y, in the vaccination schedule of these patients from 6 months after their transplant to improve their protection.

There are several meningococcal groups and therefore several vaccines recommended for HSCT patients. Evaluation of another meningococcal B vaccine, Trumenba^®, in HSCT recipients could be the next stage in research into protection against meningococcal infection.