Vaccination of children during treatment for leukemia.

Forty-one children receiving maintenance treatment for leukemia were vaccinated with inactivated mumps virus, meningococcal polysaccharide groups A and C and polyvalent pneumococcal polysaccharide vaccines. Antibodies against pneumococcal types 3, 18C, 19F and 23F and against meningococcal groups A and C were measured by radioimmunoassay. Mumps antibodies were determined by complement fixation, hemolysis-in-gel and enzyme-linked immunosorbent assays. The antibody responses tended to be lower than those of healthy age-matched controls. The individual responses were unpredictable; the magnitude of the response correlated neither with the age nor sex of the patient, duration of the chemotherapy nor with the prevaccination antibody concentration. Nevertheless, most patients achieved and even exceeded the geometric mean of the antibody concentrations of the healthy children, considered protective against infection.