Benn Christine S, Aaby Peter, Nielsen Jens, Binka Fred N, Ross David A
Statens Serum Institut, Copenhagen, Denmark.
Am J Clin Nutr. 2009 Sep;90(3):629-39. doi: 10.3945/ajcn.2009.27477. Epub 2009 Jul 29.
The World Health Organization recommends vitamin A supplementation (VAS) at vaccination contacts after 6 mo of age to reduce mortality. However, it is unknown whether the effect of VAS is independent of vaccinations. One of the original VAS trials from Ghana had collected vaccination information.
We reanalyzed the data to explore the hypothesis that VAS reduces mortality in children who had bacille Calmette-Guérin or measles vaccine as their most recent vaccine but increased mortality when diphtheria-tetanus-pertussis vaccine (DTP) was the most recent vaccine. On the basis of previous studies, we expected the effects to be strongest in girls.
At enrollment, children aged 6-90 mo were randomly assigned to receive VAS or placebo every 4 mo for 2 y. Vaccination status was assessed at enrollment and after 1 and 2 y by reviewing the children's health cards. Lack of a health card was presumed to mean that the child had not been vaccinated.
VAS had a beneficial effect only in children with no record of vaccination at enrollment (n = 5066); the mortality rate ratio (MRR) was 0.64 (95% CI: 0.47, 0.88) compared with 0.95 (95% CI: 0.72, 1.26) in children with one or more vaccinations (n = 6656). Among vaccinated children, the effect of VAS differed between boys (MRR: 0.74; 95% CI: 0.51, 1.08) and girls (MRR: 1.18; 95% CI: 0.84, 1.67) (P = 0.046 for interaction). VAS had a negative effect in measles-vaccinated girls who were missing one or more doses of DTP at enrollment, a group who often received DTP during follow-up (MRR: 2.60; 95% CI: 1.41, 4.80).
The effect of VAS differed by vaccination status. This is potentially problematic because VAS is provided at vaccination contacts.
世界卫生组织建议在6月龄后每次接种疫苗时补充维生素A（VAS）以降低死亡率。然而，VAS的效果是否独立于疫苗接种尚不清楚。来自加纳的一项最初的VAS试验收集了疫苗接种信息。
我们重新分析数据，以探讨以下假设：VAS可降低以卡介苗或麻疹疫苗作为最近一次接种疫苗的儿童的死亡率，但当白喉-破伤风-百日咳疫苗（DTP）为最近一次接种疫苗时，VAS会增加死亡率。基于之前的研究，我们预计这种影响在女孩中最为明显。
在入组时，将6至90月龄的儿童随机分配，每4个月接受一次VAS或安慰剂，共2年。通过查看儿童健康卡，在入组时以及1年和2年后评估疫苗接种状况。没有健康卡被推测意味着该儿童未接种疫苗。
VAS仅对入组时无疫苗接种记录的儿童（n = 5066）有有益影响；死亡率比（MRR）为0.64（95%CI：0.47，0.88），而有一次或多次疫苗接种的儿童（n = 6656）的死亡率比为0.95（95%CI：0.72，1.26）。在接种疫苗的儿童中，VAS对男孩（MRR：0.74；95%CI：0.51，1.08）和女孩（MRR：1.18；95%CI：0.84，1.67）的影响不同（交互作用P = 0.046）。VAS对入组时漏种一剂或多剂DTP的麻疹疫苗接种女孩有负面影响，这组儿童在随访期间经常接种DTP（MRR：2.60；95%CI：1.41，4.80）。
VAS的效果因疫苗接种状况而异。这可能存在问题，因为VAS是在接种疫苗时提供的。
