Agence de Medecine Preventive (AMP), Paris, France.
Vaccine. 2013 Jul 11;31(32):3222-8. doi: 10.1016/j.vaccine.2013.05.017. Epub 2013 May 22.
There is an increasing focus on influenza in low-resourced areas as a vaccine-preventable cause of severe lower respiratory disease in young children, especially among those under two years of age. The extent of the disease burden is unclear: current etiologic studies may underestimate the impact of influenza if recognized or unrecognized infection occurs some time before severe disease manifestations prompt specimen collection for diagnosis. Because of various methodological challenges, a vaccine probe approach was used to estimate vaccine preventable disease incidence (VPDI) for Streptococcus pneumoniae and Haemophilus influenzae type b, particularly for pneumonia outcomes among young children. A similar approach could be used to determine VPDI for influenza. A highly effective vaccine would facilitate this approach; however, with appropriate design, a less than ideal vaccine also could be used to estimate VPDI. Because influenza vaccine efficacy against severe disease may be greater than against all symptomatic influenza disease, a vaccine probe approach could provide a better measure than etiologic studies of the public health utility of influenza vaccine. The first 6 months of life is a time of particularly increased influenza risk among young children, and an age group for which current vaccines are not approved. Previous studies have found that maternal influenza immunization can reduce acute respiratory infection in the infant during this vulnerable period. Additional randomized, controlled trials are currently underway using a vaccine probe approach to estimate VPDI among mothers and their infants following maternal influenza immunization. The World Health Organization now identifies pregnant women as the highest priority target group for influenza vaccination. Should countries implement this strategy, infants age 6-23 months likely would remain at increased risk; vaccine probe approaches could quantify the public health benefit of immunizing this group.
人们越来越关注资源匮乏地区的流感，因为流感是导致幼儿严重下呼吸道疾病（尤其是两岁以下儿童）的可预防病因。疾病负担程度尚不清楚：如果在出现严重疾病表现促使采集标本进行诊断之前，已经发生了可识别或未识别的感染，那么目前的病因研究可能低估了流感的影响。由于存在各种方法学挑战，人们采用疫苗探测方法来估计肺炎球菌和乙型流感嗜血杆菌（尤其是针对幼儿肺炎结局）的疫苗可预防疾病发病率（VPDI）。也可以采用类似方法来确定流感的 VPDI。一种高度有效的疫苗将有助于采用这种方法；然而，如果设计适当，即使疫苗效果不太理想，也可以用于估计 VPDI。由于流感疫苗对严重疾病的功效可能大于对所有有症状流感疾病的功效，因此疫苗探测方法可能比病因研究更能衡量流感疫苗对公共卫生的效用。生命的头 6 个月是幼儿流感风险特别增加的时期，而目前的疫苗不适用于该年龄组。先前的研究发现，母亲接种流感疫苗可以减少婴儿在此脆弱时期的急性呼吸道感染。目前正在进行更多的随机对照试验，采用疫苗探测方法，根据母亲接种流感疫苗后，来估计母亲及其婴儿的 VPDI。世界卫生组织现在将孕妇确定为流感疫苗接种的最高优先目标人群。如果各国实施这一策略，6-23 月龄婴儿可能仍面临较高风险；疫苗探测方法可以量化为该人群接种疫苗的公共卫生效益。
