Deficits in Long-Term Vaccine Immunity Among Childhood Cancer Survivors Despite Revaccination Programs.

Area of Science:

• Immunology
• Pediatric Oncology
• Vaccinology

Background:

• Childhood cancer survivors (CCSs) face increased risk of vaccine-preventable diseases due to impaired humoral immunity from cancer treatments.
• Assessing seroprevalence of tetanus and rubella antibodies in CCSs is crucial for understanding their vulnerability.

Purpose of the Study:

• To compare tetanus and rubella antibody seroprevalence in CCSs versus healthy controls.
• To investigate the impact of cancer treatments and revaccination on vaccine-induced immunity in CCSs.

Main Methods:

• Retrospective analysis of 180 CCSs treated at Astrid Lindgren Children's Hospital (March 2019-January 2023).
• Comparison of CCS seroprevalence data with a national seroprevalence study for the 15-19-year age group.
• Evaluation of revaccination status and its effect on antibody levels.

Main Results:

• CCSs showed significantly lower seroprevalence for tetanus (77.7%) and rubella (79.1%) compared to controls (92.7% and 97.5%).
• Intensive chemotherapy was associated with the lowest tetanus and rubella antibody levels.
• While DTP revaccination improved tetanus immunity, MMR revaccination had a limited impact on rubella immunity.

Conclusions:

• Vaccine underutilization and immunity gaps are prevalent in CCSs, especially after intensive treatments.
• MMR revaccination did not significantly enhance rubella immunity in this cohort.
• Effective strategies are needed to restore vaccine immunity in the growing population of CCSs.