The Pediatric Infectious Disease Unit, the Faculty of Health Sciences, Ben-Gurion University of the Negev and Soroka University Medical Center, Beer-Sheva, Israel.
Vaccine. 2012 Jul 20;30(34):5132-40. doi: 10.1016/j.vaccine.2012.05.059. Epub 2012 Jun 6.
The 7-valent pneumococcal conjugate vaccine (PCV7) was initially licensed for use as 3 infant doses and a booster (3+1). However, 2 infant doses plus a booster schedules only (2+1) are widely used. We compared the effect of these two schedules on pneumococcal carriage in young children. We also assessed the effect of a 2-dose schedule in the second year ("catch-up" schedule; 0+2).
Subjects (n=733) were randomized to the 2+1 (4, 6, 12 m), 3+1 (2, 4, 6, 12 m) or 0+2 (12, 18 m) schedules. Blood samples for serotype-specific IgG (SSIgG) determination were obtained at 2, 7, 13, 19 months, and nasopharyngeal+oropharyngeal pneumococcal cultures were obtained at 2, 4, 6, 7, 12, 13, 18, 19, 24, 30 months.
After primary infant PCV7 series, SSIgG was significantly lower for four out of seven serotypes in children receiving 2 doses compared to 3 doses, particularly for serotypes 6B and 23F. This was associated with a higher acquisition and prevalence rates of vaccine serotype carriage in the 2-dose group, particularly serotypes 6A and 6B. After the booster dose at 12 months of age, most differences were not significant anymore. A single PCV7 dose at age 12 months in previously unvaccinated subjects ("catch up" schedule) resulted in poor SSIgG concentrations for three out of seven serotypes, resulting in higher acquisition and prevalence rates of vaccine serotypes (grouped) compared to infants receiving a booster dose at 12 months (2+1 and 3+1 groups). Similarly, serotypes 6B and 6A also showed significantly higher carriage rates after a single dose at 12 months. After the second catch-up dose at 18 months, the rates were similar to those in the 2+1 or 3+1 schedules, except for serotype 6A.
Three infant doses seem to better protect against PCV7-serotype acquisition and carriage than two. However, after booster, most of these differences disappear. A 2-dose second year catch-up campaign may enhance the reduction of PCV7-serotype spread in the community.
7 价肺炎球菌结合疫苗（PCV7）最初被批准用于接种 3 针婴儿剂量和加强针（3+1）。然而，2 针婴儿剂量加加强针（2+1）的接种方案更为广泛。我们比较了这两种方案对幼儿中肺炎球菌定植的影响。我们还评估了第二年 2 针方案（“追赶”方案；0+2）的效果。
研究对象（n=733）随机分配至 2+1（4、6、12 个月）、3+1（2、4、6、12 个月）或 0+2（12、18 个月）方案。在 2、7、13、19 个月时采集血清型特异性 IgG（SSIgG）测定的血样，在 2、4、6、7、12、13、18、19、24、30 个月时采集鼻咽+口咽肺炎球菌培养。
在初次婴儿 PCV7 系列接种后，与接种 3 针相比，接受 2 针的儿童有 4 种血清型中的 7 种血清型的 SSIgG 显著降低，尤其是血清型 6B 和 23F。这与 2 剂组中疫苗血清型携带的获得率和流行率较高相关，尤其是血清型 6A 和 6B。在 12 个月龄时接种加强针后，大多数差异不再显著。12 月龄时，对以前未接种过疫苗的儿童（“追赶”方案）接种单次 PCV7 剂量，导致 7 种血清型中有 3 种血清型的 SSIgG 浓度较差，导致疫苗血清型（分组）的获得率和流行率较高，与 12 个月龄时接种加强针的婴儿（2+1 和 3+1 组）相比。同样，6B 和 6A 型在 12 个月龄接种单剂后，携带率也显著升高。在 18 个月龄时接种第二次追赶剂量后，除血清型 6A 外，其携带率与 2+1 或 3+1 方案相似。
3 针婴儿剂量似乎比 2 针更能预防 PCV7 血清型的获得和定植。然而，在加强针后，这些差异大多消失。第二年的 2 针追赶接种运动可能会增强社区中 PCV7 血清型传播的减少。
