Englund Janet A, Walter Emmanuel B, Fairchok Mary P, Monto Arnold S, Neuzil Kathleen M
Division of Pediatric Infectious Diseases, Allergy, and Rheumatology, University of Washington and Children's Hospital and Regional Medical Center, Seattle, Washington 98105, USA.
Pediatrics. 2005 Apr;115(4):1039-47. doi: 10.1542/peds.2004-2373.
Trivalent inactivated influenza vaccine (TIV) is recommended for all children ages 6 to 23 months. Delivering 2 doses of TIV at least 4 weeks apart to young children receiving this vaccine for the first time is challenging.
We compared the immunogenicity and reactogenicity of the standard 2-dose regimen of TIV administered in the fall with an early schedule of a single spring dose followed by a fall dose of the same vaccine in healthy toddlers 6 to 23 months of age. Children were recruited in the spring to be randomized into either the standard or early schedule. An additional group was also enrolled in the fall as part of a nonrandomized standard comparison group. The 2002-2003 licensed TIV was administered in the spring; the fall 2003-2004 vaccine contained the same 3 antigenic components. Reactogenicity was assessed by parental diaries and telephone surveillance. Blood was obtained after the second dose of TIV for all children. The primary outcome measure was antibody response to influenza A/H1N1, A/H3N2, and B after 2 doses of vaccine, as determined by hemagglutination-inhibition titers > or =1:32 and geometric mean titer (GMT).
Two hundred nineteen children were randomized to receive either the standard or early TIV schedule; 40 additional children were enrolled in the fall in the nonrandomized standard group. Response rates in the combined standard versus early groups were similar overall: 78% (GMT: 48) vs 76% (GMT: 57) to H1N1, 89% (GMT: 115) vs 88% (GMT: 129) to H3N2, and 52% (GMT: 24) vs 60% (GMT: 28) to B. Reactogenicity after TIV in both groups of children was minimal and did not differ by dose, age, or time between doses. Reaction rates were higher in those receiving TIV and concomitant vaccines compared with those receiving TIV alone. Overall rates of fever >38 degrees C axillary and injection-site pain, redness, or swelling were 5.4%, 3.1%, 0.9%, and 1.1%, respectively.
When the spring and fall influenza vaccines had the same 3 antigenic components, the early vaccine schedule resulted in similar immunogenicity and reactogenicity compared with the standard schedule. When the vaccine components do not change between years, initiating influenza vaccine in the spring at the time of routine office visits would facilitate full immunization of children against influenza earlier in the season.
推荐所有6至23个月大的儿童接种三价灭活流感疫苗（TIV）。首次接种该疫苗的幼儿需间隔至少4周接种2剂TIV，这颇具挑战性。
我们比较了在秋季接种标准2剂次TIV方案与在春季先接种1剂次、秋季再接种1剂次相同疫苗的早期接种方案在6至23个月健康幼儿中的免疫原性和反应原性。春季招募儿童并随机分为标准组或早期组。秋季还纳入了一组作为非随机标准对照组。2002 - 2003年获批的TIV在春季接种；2003 - 2004年秋季疫苗含有相同的3种抗原成分。通过家长日记和电话随访评估反应原性。所有儿童在接种第2剂TIV后采集血液。主要观察指标是2剂疫苗接种后对甲型H1N1、甲型H3N2和乙型流感病毒的抗体反应，通过血凝抑制效价≥1:32和几何平均滴度（GMT）来确定。
219名儿童被随机分配接受标准或早期TIV接种方案；另外40名儿童在秋季纳入非随机标准组。标准组与早期组的总体反应率相似：对H1N1的反应率分别为78%（GMT：48）和76%（GMT：57），对H3N2的反应率分别为89%（GMT：115）和88%（GMT：129），对乙型流感病毒的反应率分别为52%（GMT：24）和60%（GMT：28）。两组儿童接种TIV后的反应原性均极小，且在剂量、年龄或剂次间隔时间方面无差异。与仅接种TIV的儿童相比，同时接种TIV和其他疫苗的儿童反应率更高。腋下体温>38℃以及注射部位疼痛、发红或肿胀的总体发生率分别为5.4%、3.1%、0.9%和1.1%。
当春季和秋季流感疫苗含有相同的3种抗原成分时，早期接种方案与标准方案相比，免疫原性和反应原性相似。如果疫苗成分逐年不变，在春季常规门诊时开始接种流感疫苗将有助于儿童在流感季节更早实现全面免疫。
