Vaccine boost may be needed after chemotherapy in children

Children who have undergone chemotherapy are prone to loss of protective serum antibody titers acquired from previous vaccinations, Italian researchers report in the August 1st issue of Cancer.

This finding, Dr. Matteo Zignol and colleagues from the University of Padua suggest, “may account for the failure of vaccination programs for patients who have undergone chemotherapy.”The team assessed the persistence of humoral immunity to hepatitis B, measles, mumps, rubella, tetanus, and polio in 192 children following chemotherapy for malignancies including acute lymphoblastic leukemia and Hodgkin’s lymphoma. Overall, 46% of children lacked protective serum antibody titers to hepatitis B. Corresponding proportions for measles, mumps, and rubella were 25%, 28%, and 24%. Furthermore, 14% of children lacked protective titers to tetanus and 7% lacked protective serum antibody titers to polio.In children determined to have had immunity before chemotherapy, rates of loss of protective immunity to hepatitis B, measles, mumps, rubella, tetanus, and polio were 52%, 25%, 21%, 18%, 13% and 8%.However, giving a total of 59 booster vaccinations to 51 children who had lost at least one protective antibody titer led to an overall response rate of 93%, the team reports. Thus, they conclude that administering a booster dose 12 months after chemotherapy ends is a “simple and cost-effective way to restore humoral immunity against most vaccine-preventable diseases.”(Source: Cancer 2004;101:635-641: Reuters Health: Oncolink: August 2004.)