Safety and immunogenicity of live attenuated and inactivated influenza vaccines in children with cancer.

BACKGROUND: The safety and immunogenicity of live, attenuated influenza vaccine (LAIV) has not been compared to that of the standard trivalent inactivated vaccine (TIV) in children with cancer. METHODS: Randomized study of LAIV versus TIV in children with cancer, age 2-21 years, vaccinated according to recommendations based on age and prior vaccination. Data on reactogenicity and other adverse events and blood and nasal swab samples were obtained following vaccination. RESULTS: Fifty-five eligible subjects (mean age, 10.4 years) received vaccine (28 LAIV/27 TIV). Both vaccines were well tolerated. Rhinorrhea reported within 10 days of vaccination was similar in both groups (36% LAIV vs 33% TIV, P > .999). Ten LAIV recipients shed virus; the latest viral shedding was detected 7 days after vaccination. Immunogenicity data were available for 52 subjects, or 26 in each group. TIV induced significantly higher postvaccination geometric mean titers against influenza A viruses (P < .001), greater seroprotection against influenza A/H1N1 (P = .01), and greater seroconversion against A/H3N2 (P = .004), compared with LAIV. No differences after vaccination were observed against influenza B viruses. CONCLUSIONS: As expected, serum antibody response against influenza A strains were greater with TIV than with LAIV in children with cancer. Both vaccines were well tolerated, and prolonged viral shedding after LAIV was not detected. CLINICAL TRIALS REGISTRATION: NCT00906750.