Immunogenicity of influenza vaccine in children with pediatric rheumatic diseases receiving immunosuppressive agents.

BACKGROUND: Children with rheumatic diseases receiving immunosuppressive therapy are a high-risk group for influenza virus infection; however, few data are available regarding the efficacy and safety of influenza vaccine for those individuals.
METHODS: This was a prospective study evaluating the immunogenicity and safety of influenza vaccine in 49 children (mean ± standard deviation: 12.1 ± 4.8 years, age range: 0-21 years) with pediatric rheumatic diseases including juvenile idiopathic arthritis (n = 23), systemic lupus erythematosus (n = 12), juvenile dermatomyositis (n = 6), and others (n = 8), who were receiving immunosuppressive therapies. A total of 36 healthy children were selected as a control. The influenza virus type-A and B antibody titers were measured using hemagglutinin inhibition before and after the vaccination.
RESULTS: There were no significant differences in the percentage of vaccine recipients with an increase in the serum titers ≥ 4× after vaccination (H1N1, H3N2, and B strain) between the 2 groups (P = 0.49, P = 0.25, P = 0.56, respectively), demonstrating similar immunogenicity of the influenza vaccination between patients and control groups. There were no serious adverse effects related to the vaccine in either group.
CONCLUSIONS: In the children with pediatric rheumatic diseases receiving immunosuppressive agents, influenza vaccination resulted in serum antibody titers similar to those in the controls without major adverse effects. Such children receiving immunosuppressive therapy are a high-risk group for influenza virus infection, therefore vaccine should be given.