METHODS: In this randomised controlled trial, 180 Swedish formula-fed infants received, from 6 weeks to 6 months of age, a 2 mg/L iron formula with (n = 72) or without (n = 72) bovine lactoferrin, or a control formula with 8 mg/L iron and no lactoferrin (n = 36). Another 72 infants were recruited as a breastfed reference. Serum immunoglobulin G (IgG) levels against Haemophilus influenzae type b (Hib), diphtheria and tetanus were assessed at four, six and 12 months of age.
RESULTS: With an equal gender distribution, 180 + 72 term infants were included with a mean age of 7.0 ± 0.7 weeks. At 12 months, infants fed low iron formula showed a significantly higher geometric mean Hib IgG (1.40 μg/mL [1.07-1.83]) compared to the control formula infants (0.67 μg/mL [0.42-1.07]). For all three vaccines, breastfed infants had significantly lower IgG levels at six and 12 months of age.
CONCLUSIONS: Except for higher Hib IgG levels at 12 months in infants fed low iron formula, the interventions did not affect vaccine IgG response. Unexpectedly, breastfed infants had significantly lower vaccine IgG levels compared to formula-fed infants.
方法:在这项随机对照试验中,收到180名瑞典配方奶粉喂养的婴儿,从6周到6个月大,含(n=72)或不含(n=72)牛乳铁蛋白的2mg/L铁配方,或具有8mg/L铁且无乳铁蛋白的对照配方(n=36)。另外72名婴儿被招募作为母乳喂养的参考。血清免疫球蛋白G(IgG)水平对b型流感嗜血杆菌(Hib),四时评估白喉和破伤风,6个月和12个月大。
结果:性别分布平等,包括180+72名足月儿,平均年龄为7.0±0.7周。12个月时,与对照配方奶粉婴儿(0.67μg/mL[0.42-1.07])相比,低铁配方奶粉喂养的婴儿显示出显著更高的几何平均HibIgG(1.40μg/mL[1.07-1.83]).对于所有三种疫苗,母乳喂养的婴儿在6个月和12个月时IgG水平显著降低.
结论:除了低铁配方喂养的婴儿在12个月时HibIgG水平较高,干预措施未影响疫苗IgG应答.出乎意料的是,母乳喂养婴儿的疫苗IgG水平显著低于配方喂养婴儿.