据3月10日刊JAMA上的一则研究披露，与儿童没有接种流感疫苗的类似社区相比，那些对儿童和青少年接种灭活流感疫苗的社区可降低其所在社区的流感发病率，这表明，给儿童接种疫苗可帮助防止流感病毒的传播，并给社区中未接种疫苗的居民提供保护。
文章的作者写道，儿童和青少年看来在流感的传播上扮演着某种重要的角色，而且对这一群体实行选择性的流感疫苗接种可中断流感病毒的传播并保护那些未接种疫苗的人。
McMaster University, Hamilton, Ontario, Canada的Mark Loeb, M.D., M.Sc.及其同僚对给儿童和青少年接种灭活流感疫苗是否能够帮助预防社区中的其他成员罹患流感进行了评估。由于随机测试所有社区儿童青少年的接种流感疫苗的间接益处在大多数的情况下是不可行的，因此，研究人员决定在Hutterite（再洗礼宗派）的聚居地开展他们的研究，这些聚居地大多位于加拿大西部的农村社区之中。文章的作者写道：“这些关系紧密的社区类似于扩大的家庭，但却由单一的每户居住在他们自己房屋内的家庭所组成。那里的年龄3-15岁的儿童和青少年会上学读书。每个聚居地中居住着大约60-120人。”
这一试验包括了在Alberta, Saskatchewan 和 Manitoba 的49个Hutterite 聚居地中的947名年龄在3-15岁的接种了研究用疫苗的加拿大儿童和青少年，以及没有接种研究疫苗的2326名社区中的其他成员。对他们的跟踪随访从2008年12月开始，并在2009年6月结束。儿童是根据社区而被随机分配接受标准剂量的灭活三价流感疫苗或是甲型肝炎疫苗，后者被当作对照。
在健康儿童集群中分配接种流感疫苗的平均疫苗覆盖率为83%，这一数字（79%）与聚居地中被指派接种甲型肝炎疫苗的平均疫苗覆盖率类似。有119名没有接种流感疫苗的人发现了由实验室确认的流感：其中39人（占3.1%）来自接种了流感疫苗的聚居地，而80人（占7.6%）来自接种了甲型肝炎的聚居地。间接的疫苗保护性功效为61%。
在所有研究的参与者中（即所有接种了疫苗或未接种疫苗的人），在接种了流感疫苗的聚居地中，有80/1773（4.5%）的人被确诊罹患流感；在接种了甲型肝炎疫苗的聚居地中，有159/1500（10.6%）的人被确诊罹患流感，而流感疫苗的总体保护性功效为59%。没有观察到流感疫苗有严重的不良反应。
文章的作者写道：“鉴于2009年甲型流感（H1N1）快速传播的情况，了解是否可通过免疫儿童而预防或减少流感的传播具有高度的优先权，这样，诸如孕妇和土著居民这样的具有高风险并发症的群体可能会因此而间接得到保护。”
我们的发现就支持选择性地为学童接种灭活流感疫苗以中断流感传播提供了实验上的证明。特别是在如果存在有疫苗数量和发送有限制的情况下，选择性地给儿童接种疫苗以降低流感在社区中的传播可能是有益的。”
原始出处：
JAMA Vol. 303 No. 10, March 10, 2010
Effect of Influenza Vaccination of Children on Infection Rates in Hutterite Communities
A Randomized Trial
Mark Loeb, MD, MSc; Margaret L. Russell, MD, PhD; Lorraine Moss, BSc; Kevin Fonseca, PhD; Julie Fox, PhD; David J. D. Earn, PhD; Fred Aoki, MD; Gregory Horsman, MD; Paul Van Caeseele, MD; Khami Chokani, MD; Mark Vooght, MD; Lorne Babiuk, PhD; Richard Webby, PhD; Stephen D. Walter, PhD
Context Children and adolescents appear to play an important role in the transmission of influenza. Selectively vaccinating youngsters against influenza may interrupt virus transmission and protect those not immunized.
Objective To assess whether vaccinating children and adolescents with inactivated influenza vaccine could prevent influenza in other community members.
Design, Setting, and Participants A cluster randomized trial involving 947 Canadian children and adolescents aged 36 months to 15 years who received study vaccine and 2326 community members who did not receive the study vaccine in 49 Hutterite colonies in Alberta, Saskatchewan, and Manitoba. Follow-up began December 28, 2008, and ended June 23, 2009.
Intervention Children were randomly assigned according to community and in a blinded manner to receive standard dosing of either inactivated trivalent influenza vaccine or hepatitis A vaccine, which was used as a control.
Main Outcome Measures Confirmed influenza A and B infection using a real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay and by measuring serum hemagglutination inhibition titers.
Results The mean rate of study vaccine coverage among eligible participants was 83% (range, 53%-100%) for the influenza vaccine colonies and 79% (range, 50%-100%) for the hepatitis A vaccine colonies. Among nonrecipients, 39 of 1271 (3.1%) in the influenza vaccine colonies and 80 of 1055 (7.6%) in the hepatitis A vaccine colonies had influenza illness confirmed by RT-PCR, for a protective effectiveness of 61% (95% confidence interval [CI], 8%-83%; P = .03). Among all study participants (those who were and those who were not vaccinated), 80 of 1773 (4.5%) in the influenza vaccine colonies and 159 of 1500 (10.6%) in the hepatitis A vaccine colonies had influenza illness confirmed by RT-PCR for an overall protective effectiveness of 59% (95% CI, 5%-82%; P = .04). No serious vaccine adverse events were observed.
Conclusion Immunizing children and adolescents with inactivated influenza vaccine significantly protected unimmunized residents of rural communities against influenza.
