Recovery of humoral and cellular immunities to vaccine-preventable infectious diseases in pediatric oncology patients.

The recovery of antibodies to various vaccine-preventable infectious diseases, humoral and cellular immunity in pediatric oncology patients were evaluated by a prospective longitudinal study for 18 months. Lymphocyte subset (CD3+, CD4+, CD8+, CD16/56+, CD19+), CD4/CD8 ratio, immunoglobulin levels, antibodies to diphtheria, pertussis, tetanus, hepatitis B, measles, mumps, and rubella were measured serially at 6 months till 18 months after stopping all chemotherapy (including maintenance chemotherapy). Twenty-eight children (hematological malignancies, n = 14; solid tumors, n = 14) were studied. The median age was 7.0 +/- 3.8 years old (range 2.6-16.2 years old). Although there was significant increase in CD3+, CD4+, CD8+, CD19+ cells, IgG, IgA, and IgM levels (P < .05), CD4+ and CD8+ counts were still below the age-specific normal range at the end of study period. At 18 months after stopping chemotherapy, 11%, 15%, 60%, 30%, 49%, and 30% of subjects remained seronegative against diphtheria, tetanus, hepatitis B, measles, mumps, and rubella. This will evolve to a significant health care problem if no further intervention is implemented, as the survival rate of pediatric oncology patients improves significantly with the improvement in various cancer treatment protocols. Near complete immune recovery was demonstrated in the subjects. Significant proportion of subjects remained susceptible to vaccine-preventable infectious diseases up to 18 months after stopping all chemotherapy.