Assessment of Influenza Vaccine Immunogenicity in Immunocompromized Host During 2009 Influenza Season: A Single Institution Experience / 소아감염

ABSTRACT

PURPOSE: Although influenza is regarded as one of the major causes of morbidity and mortality in children with cancer, the actual vaccine coverage remains poor. We conducted evaluation of immunogenicity and safety of influenza vaccine in children with cancer. METHODS: In this study, 25 children with cancer who received influenza vaccine (SK influenza IX vaccine(R)) at the Korea Cancer Center Hospital between October and December 2009 were analyzed. Blood samples of patients were collected twice (at the beginning of this study and at 30th day after vaccination) and their antibody titers were measured using the hemagglutination-inhibition (HI) assay. Immunogenicity of the influenza vaccine was assessed by seroprotection rate on days 0 and 30, seroconversion rate on day 30, and mean fold increase (MFI) of geometric mean titer (GMT) of HI between days 0 and 30. RESULTS: Any of the subjects in our study did not experienced serious adverse events after influenza vaccination. Seroprotection rates were 68% for H1N1, 40% for H3N2, and 36% for B. Seroconversion rates were 12% for H1N1, 16% for H3N2, and 20% for B. MFIs were 0.9 for H1N1, 1.2 for H3N2, and 1.8 for B. CONCLUSION: In the study, we found a limited protective immune response to influenza vaccine, among subjects with cancer. However, some subjects showed seroconversion, and there were no severe adverse events among all subjects, supporting the recommendation of annual influenza vaccination in children with cancer.