Long-term immunogenicity of a virosomal subunit inactivated influenza vaccine in children with asthma
- 作者：Gianvincenzo Zuccotti ; Antonella Amendola ; Aless ; ra Viganò ; Elena Pariani ; Aless ; ra Zappa ; Laura Pogliani ; Vania Giacomet ; Antonino Savarino ; Alberto Podestà ; Amilcare Rottoli ; Elisabetta Ta
- 关键词：Asthma ; Children ; Virosomal vaccine
- 刊名：Vaccine
- 出版年：2007
- 期刊代码：89_0264410x
- 类别：imm
- 出版时间：17 September 2007
- 卷：25
- 期：37-38
- 页码：6692-6698
- 文件大小：206 K
摘要
To evaluate long-term immunogenicity of a virosomal subunit inactivated influenza vaccine in children with asthma, a prospective study was conducted during 2005–2006 influenza season in six public pediatric clinics in Milan and surroundings, Northern Italy. A single dose (0.5 ml) of a virosomal subunit inactivated influenza vaccine (Inflexal V®) was injected in 106 asthmatic children aged 3–9 years. Serum hemagglutinin inhibition antibody titers were determined against the recommended influenza strains A/New Caledonia (H1N1), A/California (H3N2), and B/Shanghai (B), at pre-vaccination and 1 and 6 months after vaccination. Seroconversion rate (95%CI) against the strains A/H1N1, A/H3N2 and B was, respectively, 78%(68.6–85.7), 57%(46.7–66.9) and 66%(55.8–71.2) at 1 month. Seroprotection (titer ≥ 40) rate for A/H1N1, A/H3N2 and B was, respectively, 87%(77.8–92.2), 82%(72.6–89.7) and 90%(82.6–94.8) at 1 month and 74%(64.3–82.3), 77%(67.5–84.8), and 77%(67.5–84.8) at 6 months. Seroprotection rate was high and persistent (>95%) in children with pre-existing antibodies (titer ≥ 10) at pre-vaccination for any specific strain. In children without pre-existing antibodies, seroprotection rate for A/H1N1, A/H3N2 and B was, respectively, 67.6%, 66.7%and 74.4%at 1 month, and 35.1%, 56.2%and 41.0%at 6 months after vaccination. Vaccine was well tolerated. These results indicate that in unvaccinated children with asthma vaccination with a single dose of virosomal-adjuvanted influenza vaccine is well tolerated and effective as a whole. However, while immunity response and persistence are excellently high in children with pre-existing antibodies, in children naive for the antigens the immune parameters are lower at 6 months after vaccination.