Background: Patients subject to bone marrow transplantation (BMT) and other blood stem cell transplantations are severely immunocompromised after transplantation. Some studies have suggested that post-transplantation loss of acquired immunity may play a role. The objective of this study was to determine the susceptibility to vaccine-preventable diseases in people subject to BMT and the serologic response after vaccination.
Patients and method: Study population was people subject to transplantation at least 6 months before initiating vaccination and without immunosuppressive treatment at that time. A prevaccination serologic analysis was carried out, and the hepatitis B, the adult tetanus-diphtheria (Td), the IPV, the influenza and the pneumococccal vaccines were administered in accordance with standard guidelines Depending on the immune status of the patient according to the serologic analysis, the MMR vaccine was administered no sooner than 18 months after transplantation. After vaccination, a serologic analysis was carried out to determine the response.
Results: The mean time SD between transplant and the initiation of vaccination was 3.2 2.9 years. Of the 122 recipients of BMT (average age 35.8 13 years; 54.2% male), 51.7% received an allogenic and 48.3% an autologous transplant. Before vaccination, the susceptibility was 48.2% for tetanus, 66.7% for diphtheria, 74.1% for pertussis, 85.9% for hepatitis B, 13.4% for measles, 36.7% for rubella and 9.2% for mumps. The rates of seroconversion with protective titers after vaccination for tetanus, diphtheria and hepatitis B were 94%, 67% and 75% respectively. The response to the MMR vaccine was greater than 70%, with a second dose of the vaccine being needed in 26% of patients.
Conclusions: Susceptibility to vaccine-preventable diseases in transplanted patients is high. The acceptable response to vaccination justifies the development of specific programs. Given the special characteristics of this group of patients, vaccination programs must be simple and flexible.